NEUR533 - The Brain and Motivation extras Flashcards
What is hypovolemia?
A decrease in blood volume
Is anti-diuretic hormone (ADH or vasopressin) humoral?
Yes
Where do the mechanoreceptors from major blood vessels signal that there is a drop in blood pressure in the brain stem?
Nucleus of the solitary tract
Where do low BP from kidney angiotensin II signals go to first and second?
- Subfornical organ
- hypothalamus
What does a loss of vasopressin-secreting neurons of the hypothalamus cause?
Diabetes
strong motivation to drink water
What does ghrelin activate in the cephalic phase in the arcuate nucleus?
NPY/AgRP
research has found the anterior commissure and suprachiasmatic nucleus to be ____________ in male homosexuals than in male heterosexuals.
larger
Other research has found the ____________ and __________ to be larger in male homosexuals than in male heterosexuals.
Anterior commissure
SCN
One study reported that the bed nucleus of the _________ is larger in men than women and that male-to-female transsexuals have a nucleus comparable in size to females.
stria terminalis
Where is the retinotopic map processed?
In different regions of V1
Where are colour sensitive neurons located?
V4
The first site of major convergence of inputs from both eyes is in the projection of _______ cells onto cells in layer III.
layer IV
These dividing cells—the neural progenitors that give rise to all the
neurons and astrocytes of the cerebral cortex all are called ____________
radial glial cells.
The choreography of cell proliferation.
The sources of cortical cells
draw
Proliferation of cortical pyramidal neurons and astrocytes occurs in the ________ of the ______ telencephalon
ventricular zone
dorsal
However, in- hibitory interneurons and oligodendroglia are generated in the ventricular zone of the _________ telencephalon
ventral
The first cells to mi- grate away from the dorsal ventricular zone are destined to reside in a layer called the __________
The next cells to divide become __________ neurons, followed by the neurons of layers V, IV, III, and II.
subplate
layer VI
The neurons deriving from the subventricular zone are destined for the upper layers of the cortex ___________, which, in the adult brain, are the source of corticocortical connections that connect cytoarchitecturally distinct areas.
(layers II–III)
LEARN AND DRAW
KNOW AND DRAW
two complementary gradients of transcription factors, called ___________, have been discovered along the anterior–posterior axis of the ventricular zone of the developing neocortex
Emx2 and Pax6
Neurons destined for the anterior region of neocortex express higher levels of ________, and neurons destined for posterior cortex express higher levels of __________
Recall that differences in transcription factors lead to differences in gene expres- sion and protein production; these can be used as signals to attract neu- ral precursor cells to the appropriate destinations.
Pax6 (frontal cortex)
Emx2 (visual cortex)
Think Emx2 = earlier times = posterior cortex comes first
Pax6 = comes after e = later development = anterior cortex
REVIEW AND DRAW???
What is the the radial unit hypothesis?
The concept that an entire radial column of cortical neurons originates from the same birthplace in the ventricular zone
review
retinal ganglion cells
Genesis of neural connection in the central nervous system (CNS occurs in three phases:
pathway selection,
target selection, and
address selection.
(PTA meeting)
What is retinal neurogenesis phase 1?
PATHWAY SELECTION
E.G. DORSAL THALAMUS
Axon must choose corret path
What is retinal neurogenesis phase 2?
TARGET SELECTION
E.G. LATERAL GENICULATE NUCLEUS *(LGN)
Axon must choose correct structure to innovate
What is retinal neurogenesis phase 3?
ADDRESS SELECTION
E.G. CORRECT LAYER OF LGN
Axon must choose correct cells to synapse with
What is the growing tip of a neurite called?
growth cone
The leading edge of the growth cone consists of flat sheets of membrane called_____________. that undulate in rhythmic waves like the wings of a stingray swimming along the ocean bottom
lamellipodia
Extending from the lamellipodia are thin spikes called_____________, which constantly probe the environment, moving in and out of the lamellipodia
filopodia
Growth of the neurite occurs when a _______________, instead of retracting, takes hold of the substrate (the surface on which it is growing) and pulls the advancing growth cone forward.
filopodium
Growth occurs only if the extracellular matrix contains the appropriate proteins. An example of a permissive substrate is the glycoprotein_______________. The growing axons express special surface molecules called_______________ that bind laminin, and this interaction pro- motes axonal elongation.
laminin
integrins
What is fasciculation?
a mechanism that causes axons growing together to stick together
Fasciculation is due to the expression of specific surface molecules called cell-adhesion molecules _____________. The CAMs in the membrane of neighboring axons bind tightly to one another, causing the axons to grow in unison.
(CAMs)
Chemoattraction and chemorepulsion.
REVIEW
proteins called__________ are one repulsive signal for temporal retinal axons.
ephrins
When the growth cone comes in contact with its target, a _________ is formed.
synapse
YOUTUBE AND WRITE DOWN SYNAPSE FORMATION
What are the 3 steps in the formation of a CNS synapse?
- Dendritic filopodium contacts axon
- Contact = ^ synaptic vessicles and ^ active zone proteins
@ presynaptic membrane
- NT receptors accumulate post-synaptically
Matching inputs with targets by selective cell death.
A peptide called ______________ was the first trophic factor to be identified in the 1940s by Italian biologist Rita Levi-Montalcini.
nerve growth factor (NGF)
NGF is one of a family of related trophic proteins collectively called _________. Family members include the proteins NT-3, NT-4, and brain-derived neurotrophic factor (BDNF), which is important for the survival of visual cortical neurons.
neurotrophins
The important discovery of cell death genes by _____________- at the Massachusetts Institute of Technology was recognized with the 2004 Nobel Prize.
Robert Horvitz
Plasticity at Hebb synapses.
Modification of ocular dominance stripes after monocular deprivation.
Competition in visual cortex is demonstrated by the effects of ___________, a condition in which the eyes are not perfectly aligned (i.e., they are “cross-eyed” or “wall-eyed”).
strabismus
The dependence of plasticity of binocular connections on modulatory inputs
Glutamate receptors at excitatory synapses.
NMDA receptors activated by simulta- neous presynaptic and postsynaptic activity.
Does NMDA or AMPA receptors have Mg++ ions blocking ionic flow?
NMDA
the NMDA receptor channel requires the concurrent release of glutamate by the presynaptic terminal and depolarization of the ___________ membrane.
postsynaptic
The other distinguish- ing feature of an NMDA receptor is that its channel conducts ___________. Therefore, the magnitude of the ________ flux passing through the NMDA receptor channel specifically signals the level of pre- and postsynaptic coactivation.
Ca2
Ca2
when a glutamatergic synapse first forms, only ___________ receptors appear in the postsynaptic membrane.
NMDA
NMDA receptors regulates what 3 ions
Na^+, K^+, and Ca^2+
What ions are AMPA receptors associated with?
Primarily Na^+ and some K^+
Differences between AMPA and NMDA receptors - write this out
A consequence of strong _________ receptor activation is a strengthening of synaptic trans- mission called long-term potentiation (LTP).
NMDA
= flooding of Ca++ into post synaptic membrane
= New AMPA receptors
What receptor comes first in LTP? NMDA or AMPA
NMDA
then AMPA
The lasting synaptic effects of strong NMDA receptor activation.
experiments suggest that the lower level of _______ triggers an opposite form of synaptic plasticity, long-term depression (LTD),
Ca2
One consequence of LTD induction is a loss of_________ receptors from the synapse
AMPA
How brief monocular deprivation leads to reduced visual responsiveness.
3 reasons why CRITICAL BRAIN WIRING PERIODS END
- Plasticity diminishes when axon growth ceases.
- Plasticity diminishes when synaptic transmission matures
- Plasticity diminishes when cortical activation is constrained.
Where is renin produced in ?
Kidneys
Where is ACE and what does it do?
ACE - lungs
Converts Aniotensin I to AngII
What is the number 1 vasoconstrictor in your body?
ANgII
Revice the role of ACE - draw it out
Vasodilation with ACE inhibitors
Angiotensin II and it’s receptors
What type of receptor is the AT1-R (angiotensin II, type I receptor) ?
GPCR
How are AT1-Rs proposed to promote cardiomyocyte hypertrophy?
- What’s going on with stretch?
How do AT1-Rs promote cardiomyocyte hypertrophy?
