Exam 2 Flashcards
1
Q
6 Stages of Brain Development
A
- Neurogenesis
- Cell Migration
- Cell Differentiation
- Synaptogenesis
- Cell Death
- Synapse Rearrangement
2
Q
Neurogenesis
A
First Stage of Brain Development
Mitosis produces neurons from non-neuronal cells, forming the ventricular zone
3
Q
Cell Migration
A
Stage 2 of Brain Development
Cells move out of the ventricular zone toward their destination, where they form distinct populations of neurons
4
Q
Cell Differentiation
A
Stage 3 of Brain Development
Cells express particular genes and become distinctive types of.neurons or glial cells through cell-cell interactions
5
Q
Synaptogenesis
A
Stage 4 of Brain Development
Establishment of synaptic connections
6
Q
Cell Death
A
Stage 5 of Brain Development
Selective death of many neurons
7
Q
Synapse Rearrangement
A
Stage 6 of Brain Development
Loss or development of synapses, fine-tuning
Neurons compete for synaptic connections and neurotrophic factors
8
Q
Brain development 50-60 days after conceptions
A
Head is 1/2 total size of the embryo
The 5 main brain divisions are visible
9
Q
5 main brain divisions
A
Telencephalon
Diencephalon
Mesencephalon (midbrain)
Metencephalon
Myelencephalon
10
Q
Neurotrophic factors
A
Produced by different target cell groups
Regulate the expression of various genes, affecting the development of the neuron
Developing neurons that don’t get enough die
11
Q
Hebbian Synapse
A
Some synapses fire together synchronously, which drives the postsynaptic neuron to fire
Because they are more successful at driving the postsynaptic neuron, their synapses become stronger
12
Q
Number of synapses from late childhood to mid adolescence
A
Net loss
13
Q
Maturation of _________ occurs last
A
the prefrontal cortex
14
Q
When does synapse rearrangement happen?
A
Throughout adulthood
15
Q
Number of layers in the mature cerebral cortex
A
6
16
Q
Cortical tissue thinning
A
Continues from caudal to rostral throughout maturation
A layer of gray matter on the surface of the brain gets thinner as synapses are retracted
17
Q
Adaptivity of a net loss of synapses during development
A
Retaining too many synapses can impair intellectual functioning
Fragile X Syndrome is an example
18
Q
Fragile X Syndrome
A
Why too many synapses are bad
Intellectual disability due to an excess of small immature dendritic spines
19
Q
epigenetics
A
the study of the factors that change gene expression without changing the gene sequences
20
Q
methylation
A
modification of DNA without changing the nucleotide sequence
21
Q
Brain changes after age 60
A
Greater variability in brain volume decline
Hippocampus declines a lot suddenly
22
Q
Sex differences in aging brain
A
Men:
- greater reduction in prefrontal cortex volume
- more atrophy in the hypothalamus and cingulate cortex
-greater width and depth of sulci
Women:
- greater risk of Alzheimer’s
23
Q
Decrease in testosterone in elderly men
A
associative with greater cognitive decline
24
Q
Alzheimer’s Disease
A
Form of dementia associated with cortical atrophy and reduced metabolism
25
Cellular changes in Alzheimer's
Patches of amyloid plaques formed by beta-amyloid buildup
Neurofibrillary tangles
Loss of neurons that make acetylcholine in the basal forebrain
26
Neurofibrillary tangles
Intracellular sign of Alzheimer's
Alter capacity of neurons to transport nutrients, toxic to cell
27
Amyloid plaques
INTERcellular sign of Alzheimer's
Misfolded proteins on the cell membrane disrupt the synapse
28
Location of tau tangles and amyloid plaques
Lots in the cortex and hippocampus
29
Two types of chemical communication
synaptic and endocrine
30
Pheromone
chemicals released outside the body to affect other individuals of the same species
31
Allomones
chemicals released outside of the body to affect individuals of ANOTHER species
32
Peptide hormone
Short string of amino acids
33
Peptide hormone examples
Corticotropin-releasing hormone (CRH)
Gonadotropin-releasing hormone (GnRH)
34
Amine hormones
a modified version of a single amino acid, also called monoamine hormones
35
Amine hormone example
norepinephrine
(AKA Neural hormone)
36
Steroid hormone
derived from cholesterol
37
Steroid hormone examples
Estrogens
Progestins
Androgens
All lipid soluble
38
Protein and amine hormone mode of action
Attach to receptor, activate G-protein that can either alter cell function or have other biological effects
39
Steroid hormone mode of action
Can enter the cell and nucleus directly
Can alter gene expression
40
Hormone secretion by the posterior pituitary
Cell bodies in the hypothalamus
Axons pass through the pituitary stalk
Terminate on the capillaries of the posterior pituitary
41
Endocrine feedback loop in the brain
Biological response produces a negative feedback onto the hypothalamus
42
Endocrine feedback loop in the brain and pituitary
Endocrine cells produce a negative feedback on both the pituitary and hypothalamus
43
Posterior pituitary hormone examples
oxytocin and vasopressin
44
Hormone release by the anterior pituitary
Connected to hypothalamus by vasculature (portal veins)
Axons flow through the median eminence to the portal veins
45
Anterior pituitary hormone examples
Prolactin
FSH and LH
TSH
ACTH
GH
46
Two types of cells in the testes
Leydig and Sertoli
47
Leydig cells
Cells in the testes that produce testosterone
48
Sertoli cells
Cells in the testes that produce sperm
49
Gonadal hormone regulation in males
Hypothalamus produces GnRH
Causes Anterior Pituitary to produce LH and FSH
FSH stimulates both Leydig and Sertoli cells
LH stimulates Leydig cells
Testosterone and other androgens are produced, and have a negative feedback on the pituitary and hypothalamus
50
Androgens promote:
Development and maintenance of male reproductive organs
Development of male secondary sex characteristics
51
Gonadal hormone regulation in females
Hypothalamus produces GnRH
The anterior pituitary produces LH and FSH
FSH stimulates ovary for egg production and Estrogen
LH stimulates ovary for regulation and ovulation, produces progesterone
Progesterone and estrogen each back negative feedbacks on the hypothalamus and pituitary
52
Estrogens promote:
Development and maintenance of female reproductive hormones
Female secondary sex characteristics
53
Progesterone prepares:
Uterus for implantation of fertilized egg
Breasts for milk secretion
54
Stages of reproductive behavior
1. Attraction & Desire
2. Arousal
3. Copulation and Orgasm
4. Resolution
55
Stage 1 of Reproductive Behavior
Sexual Attraction and Desire
Brings males and females together
Species-specific
Shaped by culture and social factors
May be synchronized with fertility
56
Estrous cycle
Estradiol increases before estrus
Progesterone, LH, and FSH are all in sync with ovulation
57
Menstrual cycles
Estradiol, LH, and FSH all in sync with ovulation
Progesterone increases during luteal phase, after ovulation
58
Proceptive behavior
During Stage 1 (sexual attraction and desire)
females advertise readiness to mate via species-typical behavior
59
Male behavior during sexual attraction and desire
staying near female, sniffing, singing, nest building
60
Stage 2 of reproductive behavior
Sexual Arousal
Two components:
1. Physiological response of sex organs
2. Subjective perception
61
Emotion and sexual arousal
Emotion plays a larger role in women than men
62
Spinal reflex and sexual arousal
Both women and men have an enhanced spinal reflex when aroused
63
Dopamine and sexual motivation
Dopamine may increase sexual motivation and stronger instigation of action
64
Stage 3 of Sexual Behavior
Copulation and Orgasm
One or more intromissions
Male ejaculation of sperm
Refractory phase
65
Intromission
male penis inserted into female vagina
66
Brain activation during male ejaculation
More activation on the right side
Also cerebellum
67
Epigenetics
The study of the factors that change gene expression without changing the gene sequences (DNA)
68
Methylation
modification of DNA without changing the nucleotide sequence
69
Hippocampal volume decline
relatively modest until age 60, until there is a sudden decline
lots of variability
70
Brain volume decline
About 5% per decade after age 40
71
Sex differences in aging brain
men show greater reduction in prefrontal cortex volume
men show more atrophy in hypothalamus and cingulate cortex
women at greater risk for Alzheimer's
72
Alzheimer's Disease
Form of dementia associated with cortical atrophy and reduced metabolism
72
Testosterone in elderly men
Decrease in testosterone in elderly men is associated with greater cognitive decline
73
Cellular changes in Alzheimer's
Amyloid plaques
Neurofibrillary tangles
loss of neurons that make acetylcholine in the basal forebrain
74
Areas with the most tau tangles and amyloid plaques
Cortex and hippocampus
75
Neurofibrillary tangles
Intracellular changes from Alzheimer's
Alter capacity of neurons to transport nutrients down the axon
76
Amyloid plaques
INTERcellular changes from Alzheimer's
Proteins on the membrane become misformed, disrupting the synapse
77
Pheromone
chemicals released outside the body to affect other individuals of the SAME species
78
Allomone
Chemicals released outside the body to affect individuals of ANOTHER species
79
Peptide hormone
Short string of amino acids
80
Peptide hormone examples
Corticotropin-releasing hormone (CRH)
Gonadotropin-releasing hormone (GnRH)
81
Amine hormones
modified version of a single amino acid, also called monoamine hormones
82
Amine hormone example
Norepinephrine
83
Steroid hormones
Derived from cholesterol
84
Steroid hormone examples
Estrogens
Progestins
Androgens
85
Two mechanisms of hormone action
Protein and Amine hormones:
activate a G-protein to initiate altered cell function or other biological effects
Steroid hormones:
Enter cell and nucleus to change protein production through altering gene expression.
86
Hormone secretion by posterior pituitary
Cell bodies in the hypothalamus
Axons go through the pituitary stalk
Action potential reaches terminal at capillaries, where hormones are released.
87
Posterior pituitary hormone examples
Oxytocin
Vasopressin
88
Hormone secretion by anterior pituitary
Cell bodies in hypothalamus
Go through median eminence
Connect to portal veins, where hormones get released
89
Anterior pituitary hormone examples
Prolactin
FSH and LH
TSH
ACTH
GH
90
Androgens promote
Development/maintenance of male reproductive organs
Secondary sex characteristics
91
FSH in males
Acts on the Sertoli cells to produce sperm
92
Sertoli cells
Cells in testes that produce sperm
93
LH in males
Acts on Leydig cells to produce testosterone
94
Leydig cells
Cells in the testes that produce testosterone
95
Estrogens promote
development/maintenance of female reproductive organs
female secondary sex characteristics
96
Progesterone prepares
uterus for implantation of egg
breasts for milk secretion
97
FSH in females
Acts on ovary to maintain eggs and follicles
98
LH in females
Acts on the ovary to regulate ovulation
99
Stages of Reproductive Behavior
1. Sexual Attraction and Desire
2. Arousal
3. Copulation and Orgasm
4. Resolution
100
Stage 1: Sexual attraction and desire
Brings males and females together
Species specific
Shaped by cultural and social factors
May be synchronized with fertility
101
Know Estrous and Menstrual Cycles
Know this fr
102
Proceptive Behavior
females advertise readiness to mate via species-typical behavior
103
Stage 2: Sexual Arousal
Two Components:
1. Physiological response of sex organs
2. Subjective perception
104
Emotion and sexual arousal
Plays a larger role in women than men
105
Sexual arousal and spinal reflex
Sexual arousal increases dopamine secretion, which activates the VTA pathway and speeds up spinal reflexes
106
Stage 3: Copulation and Orgasm
One or more intromissions
Male ejaculation
Refractory phase
107
Brain activation during human male ejaculation
More activation on right side
Also cerebellum
108
Ventromedial Hypothalamus (VMH) in female rats
Steroid action on VMH is crucial to the lordosis response:
Estrogen stimulates progesterone receptor production (mediates lordosis)
Increases dendritic trees of neurons
109
Pathway in female to cause lordosis
Estrogens activate VMH and stimulates progesterone receptors
VMH ---> periaqueductal gray ---> L5 region of the spinal cord
Spinal cord activates lordosis
110
Vomeronasal Organ (VNO)
Detects pheromones to activate male arousal
111
Pathway for male rat arousal
Information from VNO ---> medial amygdala ---> medial preoptic area (mPOA) ---> ventral midbrain ---> L5 of spinal cord ---> ejaculation
112
Testosterone effect on sexual behavior
Activational
113
Hormones involved in erectile response
Serotonin, Norepinephrine, Nitric Oxide
114
Low dose of testosterone
Can restore sexual interest and activity in both men and women
115
Larger dose of testosterone
Does not increase intensity of sexual activity
116
Organizational effects of testosterone on sexual behavior
Early secretions result in masculine behavior in adulthood
Masculinize the brain and developing genitalia
Only during sensitive periods in early development
Only just before and after birth
117
Sexual differentiation
Early process in which a fetus begins to develop a male or female body or behaviors
118
When do early gonads begin to differentiate?
1-2 months
119
SRY gene
Sex-determining region of the Y chromosome
responsible for the development of testes
ovaries form without it
120
Two hormones that masculinize the system
Testosterone
Anti-Mullerian Hormone (AMH)
121
Testosterone during development
Promotes the development of wolffian ducts
122
Anti-mullerian Hormone (AMH) during development
Induces regression of mullerian system
123
Wolffian ducts develop into...
Epididymis, vas deferens, seminal vesicles
124
Mullerian ducts develop into...
fallopian tubes, uterus, vagina
125
Other structures masculinized by testosterone
Scrotum
Penis
126
5a-reductase
Enzyme that converts testosterone into a more powerful dihydrotestosterone (DHT), required for male genitalia masculinization
127
Sequence of sexual differentiation
Genetic Sex (XX or XY)
Gonadal Sex (testes or ovaries)
Phenotypic Sex (penis, scrotum, labia, vagina, etc.)
128
Androgen Insensitivity Syndrome (AIS)
when an XY fetus has a defective gene for the androgen receptor (Still have SRY gene)
Tissues do not respond to circulating testosterone
Testes remain internal and external tissues develop as female
129
Turner's Syndrome
A person has only one sex chromosome - a single X>
No SRY gene, so the individual develops as a female
130
Congenital Adrenal Hyperplasia (CAH)
causes developing females to be exposed to excess androgens before birth
newborns have normal ovaries and no testes
131
Sexual dimorphism
Marked differences in appearance between males and females
Also apparent in the brain
132
Sexually Dimorphic nucleus of the POA
SDN-POA
In the hypothalamus
Larger in males than females
Ovulatory and copulatory behaviors
133
When is the SDN-POA formed
Sensitive period right around birth
Testosterone at this time causes it to be larger in males
134
INAH-3 and heterosexuality
Interstitial Nuclei of the Anterior Hypothalamus
Larger in men than women
Larger in hetero than homo
Could be cause or result
135
Lesbians and fetal androgens
Lesbians are generally exposed to more fetal androgens than heterosexual women
136
Fraternal birth order effect
The more older brothers a right handed boy has, the more likely he is to grow up to be gay
Influence of immune system on fetus
137
Two possible influences on gender identity and sexual orientation
Biology
Socialization
138
Testosterone effect on POA: Organizational or Activational?
Organizational
139
Homeostasis
The maintenance of a stable, balanced, internal environment
140
Negative feedback
monitoring output and reducing activity when a set point is reached
141
Allostasis
behavioral and physiological adjustments to maintain optimal functioning of a regulated system
Point itself is fluctuating, not set
(i.e. heart rate)
142
Ectotherms
Get heat from the environment
143
Endotherms
generate their own heat through internal processes
144
heterotherms
can change between endo- and ecto- thermy
145
Physiological responses to temperature examples
Shivering, skin blood flow, water evaporation
146
Behavioral responses to temperature examples
Postural changes
Temperature choice
Altering microenvironment
147
Mammalian thermoregulatory system
Receptors in skin, body core, and hypothalamus detect temperature
Transmit info to spinal cord, brainstem, and hypothalamus
If outside of normal range, then physiological and behavioral responses
148
3 Elements of mammalian thermoregulatory systems
Receptors
Neural regions
Effectors
149
Two separate thermoregulatory systems in the hypothalamus
Preoptic Area (POA)
Lateral Hypothalamus
150
Preoptic Area as a thermoregulatory system
Mediates physiological responses to cold
Shivering and vasoconstriction
151
Lateral Hypothalamus as a thermoregulatory system
Mediates behavioral regulation of temperature
Turning on heat lamps or cooling fans
152
% water in humans
50-60% (more in men)
153
Two major compartments of water in the body
Intracellular and extracellular
154
Majority of water in the body is in which compartment?
The intracellular compartment
155
Extracellular compartment of water includes:
Blood plasma
Interstitial fluid
156
Diffusion
Molecules of a substance move until a uniform concentration is achieved
157
Osmosis
Passive movement of solvent through a semipermeable membrane between solutions of different solute concentration until both sides become equal
158
Sources of fluid loss
Perspiration
Respiration
Urination
159
Osmotic thirst
When extracellular fluid becomes too salty
160
What causes osmotic thirst?
Obligatory water loss, such as perspiration, respiration, and urination
Solute concentration increases due to the volume of fluid decreasing
161
Eating _______ food can trigger osmotic thirst
Salty
162
Hormonal response to osmotic thirst
Vasopressin (ADH)
Aldosterone
163
Vasopressin (ADH)
response to osmotic thirst
Released from Posterior Pituitary
Increases water reabsorption in the kidneys and vasoconstriction
164
Aldosterone
response to osmotic thirst
Released from adrenals
Retains Na+
Stimulate salt appetite
165
Osmosensory neurons
Monitor the concentration of extracellular fluid
In the ventricular system
166
Where are osmosensory neurons located?
Organum vasculosum of the lamina terminalis (OVLT)
Hypothalamus
Positioned along ventricles
167
Hypovolemic thirst
Triggered by a loss of fluid volume, usually major losses like vomiting, extreme diarrhea, and hemorrhage
168
Baroreceptors
Detect initial drop in blood pressure that results from hypovolemic thirst
Causes heart to decrease atrial natriuretic peptide
169
Atrial natriuretic peptide (ANP)
decreased production due to low blood pressure detected by baroreceptors
Hormone that reduces BP and helps balance electrolytes
170
Responses to hypovolemic thirst
Baroreceptors detect low BP
ANP is decreased
Vasopressin (ADH)
Angiotensin II
171
Angiotensin II release
Released by kidneys as a result of decreased blood volume from hypovolemic thirst
Increases BP through vasoconstriction
causes release of vasopressin and aldosterone
172
Angiotensin II on the brain
Acts directly on the brain at the preoptic area and circumventricular organs to stimulate thirst and drinking behavior
173
What causes us to stop drinking?
Combination of feedback from mouth, throat, and gut neurons, as well as the subfornical organ of the circumventricular organs
174
Nutrients
Chemicals required for function, maintenance, and growth of the body
175
5 main nutrients
Carbs
Protein
Fat
Vitamins
Minerals
176
Glucose
The principle sugar used for energy
177
Glycogenesis
Glucose stored in the liver and muscles for the short-term
178
Regulates glycogensis
Pancreatic hormone insulin
179
Glycogenolysis
When glucose levels drop, glucagon converts glycogen back into glucose
180
Gluconeogenesis
Under prolonged food deprivation, body fat can be converted to glucose and ketones
181
Long-term storage of glucose
adipose
182
Processes that require insulin
Using glucose for energy
183
Processes that don't require insulin
Using glucose for the brain
Using fatty acids for energy
184
Amount of energy in food that is used for active behavioral processes
10-20%
185
Basal metabolism
energy used for heat production, maintenance of membrane potentials, and life-sustaining processes
186
Metabolic adaptation
Decreases basal metabolism after weight loss
187
4 phases of insulin levels
1. Basal State (Fasting)
2. Cephalic phase
3. Digestive phase
4. Absorptive phase
188
Phase 1 of Insulin Release
Basal State
Fasting
189
Phase 2 of Insulin Release
Cephalic phase
Insulin release mediated by the brain in response to seeing, smelling, or tasting food
insulin increases
190
Phase 3 of Insulin Release
Digestive Phase
Insulin release when food enters the digestive tract
Insulin increases
191
Phase 4 of Insulin Release
Absorptive Phase
Specialized liver cells (glucodetectors) signal the pancreas to release even more insulin
192
Acetylcholine release in relation to insulin
Acetylcholine activates the parasympathetic nervous system, which stimulates insulin secretion
193
Diabetes Mellitus
Results from failure of insulin to induce glucose absorption
Brain can still use glucose, but glucose builds up in the blood
Body uses fatty acids for energy
Type I
Type II
194
Type I Diabetes Mellitus
Juvenile-onset
The pancreas stops producing insulin
195
Type II Diabetes Mellitus
Adult-onset
Reduced tissue sensitivity to insulin
196
Is insulin or glucose the sole appetite signal in the body
Neither. The brain integrates information from both
197
Satiety center of the brain
Ventromedial hypothalamus (VMH)
198
Lateral Hypothalamus and hunger
Animals with lesions decrease their hunger setpoint
199
VMH and hunger
Animals with lesions increase their hunger setpoint
200
POMC Neurons
Satiety neurons when activated, inhibiting appetite and increasing metabolism
201
NPY Neurons
Hunger neurons, stimulating appetite and reducing metabolism
202
Leptin affect on hunger/satiety neurons
Produced by adipose
Activates POMC satiety Neurons
Inhibits NPY hunger neurons
Overall suppresses appetite
203
Arcuate Nucleus
Part of the Hypothalamus that has POMC and NPY neurons
204
Arcuate neurons activate...
Brainstem
Lateral Hypothalamus
Paraventricular Nucleus (PVN)
205
Activation of arcuate neurons due to leptin causes...
Increase in body temp (sympathetic nervous system)
Decrease in Feeding/Appetite
Increase in metabolic rate
206
Hormones from digestive organs important for appetite control
Ghrelin
PYY
GLP-1
207
Ghrelin
Released by endocrine cells of the stomach
Appetite stimulant by stimulating NPY
208
PYY
Released by intestinal cells
Appetite suppressant by inhibiting NPY
209
GLP-1
Released by intestinal cells
Appetite suppressant by activating POMC
210
Insulin mode of action for satiety
Reduces appetite
Activates POMC
Inhibits NPY
211
Cholesystokinin (CCK)
Released by gut
Acts on vagus nerve
Conveys distention info to to inhibit appetite
212
Cannabinoids and hunger
Increases appetite by inhibiting POMC and increasing Ghrelin production
Mesolimbocortical activity
213
Orexin
From lateral hypothalamus
Increases consumption of yummy foods
Increases consumption of foods with conditioned stimuli
214
Medial prefrontal cortex and eating
Activated due to...
conscious awareness of hunger
part of mesolimbocortical circuit
comfort foods lead to activation
215
Strategies to treat obesity
Appetite control
Increased metabolism
Inhibition of fat tissue
Reduced absorption
Reduced reward
Anti-obesity surgery
Lifestyle changes
Manipulation of gut microbiome
216
Papillae
Increase surface area on the tongue
217
Three kinds of papillae on tongue
Circumvallate
Foliate
Fungiform
218
Circumvallate papillae
Largest
Up to 11
Majority of taste buds
219
Foliate papillae
Parallel folds on sides of tongue
220
Fungiform papillae
Most abundant
Anterior portion of tongue
Can be 100s
221
Location of taste buds
Embedded in papilla walls
222
5 basic tastes
Salty
Sour
Sweet
Bitter
Umami
223
Four cell types on taste buds
Sweet/umami/bitter
Salty
Sour
Support cell
224
Sweet/umami/bitter cells
Metabotropic
Different receptors for each taste
225
Sweet receptors
heterodimer of T1R2 and T1R3
226
Bitter receptors
T2R receptors
227
Umami receptors
MGluRs (stimulated by MSG)
T1R1 and T1R3 heterodimer
(responds to most dietary amino acids)
228
Salty cells
Na+ enters through Na+ channels
TRPV1 receptor
Detects cations of other salts in food
229
Sour cells
Related to H+ ions from acids
OTOP1 channels that allow influx of protons
230
Gustatory system
extends from the tongue, to brainstem nuclei, to thalamus, and ultimately to somatosensory cortex
Labeled line system
231
Labeled line system
Single sensation has one direct input into the CNS
(Gustatory)
232
Odorants
Inhaled molecules that interact with olfactory receptor proteins on the dendrites
233
3 Types of cells in olfactory epithelium
Supporting Cells
Basal Cells
Receptor Neurons
234
Types of neurons in olfactory system
Bipolar
235
Olfactory neuron
dendrite with olfactory cilia extending into the mucosa
Metabotropic
All neurons for similar smells go to the same glomerulus
236
Olfactory axons
unmyelinated
237
Mitral cell
Transmits olfactory info to brain
238
Glumeruli in olfactory system
Located in the olfactory bulb
Adjacent glomeruli receive input from receptors that are closely related
239
How olfactory neurons are different from others
Project ipsilaterally
Don't pass through thalamus
Diverse receptor subtypes
Die and replaced into adulthood
240
ipsilateral projection
olfactory neurons
means that left nostril projects to left brain (usually its the opposite)
241
Projections of the olfactory system
Olfactory bulb
Amygdala
Primary olfactory cortex
Hypothalamus
Secondary olfactory cortex
Lateral posterior orbitofrontal cortex
242
Receptors of the VNO
Very sensitive
Metabotropic
V1R and V2R
Projects directly to the accessory olfactory bulb
243
Anosmia
inability to smell
244
Hyposmia
partial loss of smell
245
Neurological disorders with olfactory dysfunction as a symptom
Alzheimer's
Kallmann Syndrome
Traumatic Head Injury
246
Chronobiology
Study of bio rhythms
247
Biological rhythms
Regular fluctuations in any living proess
248
Circadian rhythms
About 24 hours
Sleep, body temp, hormones
249
Ultradian Rhythms
Repeat more than once a day
sleep cycles, appetite cycles
250
Infradian Rhythms
Repeat less frequently than once a day
menstruation, hibernation, migration
251
Suprachiasmatic Nucleus (SCN)
located in the hypothalamus, above the optic chiasm
Produces the circadian rhythm
252
3 cell types that light strikes
Specialized ganglion cells
Rods
Cones
253
Pathway from light to brain for circadian rhythm
Light hits specialized ganglion cells
Travel through retinohypothalamic tract
Carries information to SCN
254
24 Hour Molecular Clock
Clock and Cycle dimerize
Dimer binds to DNA, enhancing transcription of Period and Cry genes
Period and Cry Dimerize, which inhibits clock and cycle
They eventually break down, increasing clock and cycle and starting the clock again
Glutamate from the retinohypothalamic terminal can also increase Period transcription to affect the cycle (from light)
255
Per gene expression
Higher during subjective day
256
Other tissues synchronized by SCN
liver and kidney
257
Why do animals sleep?
Conserve energy
Ecological niche
Restorative function
Memory consolidation
258
Awake waves
Mixture of low amplitude waves with many fast frequencies
259
Stage 1 of Sleep
Small amplitude
Irregular frequency
Heart rate slows, muscles, relax, eyes roll
Few minutes
260
Stage 2 of sleep
Sleep spindles
K-complexes (sharp EEG potentials)
261
Stage 3 of sleep
Large amplitude, very slow waves
1 Hour
262
REM sleep
Small amplitude
High frequency
Eyes dart rapidly
All other muscles relaxed
263
Sleep differences between young adults and elderly
Shorter awakenings for young adults
Less REM and stage 3 for elderly
