2.6 Lundy Ch. 3 (2) Flashcards
ACh is the primary conveyer of information in the (CNS/PNS)
PNS
acetylcholine: fast acting effects in the PNS
effects on skeletal muscle membranes
acetylcholine: slow acting effects in the PNS
regulation of HR and other autonomic functions
In the CNS, ACh is produced by neurons in the
- basal forebrain
- midbrain
Slow action and neuromodulation by ACh in the CNS are involved in:
- control of movement
- selection of objects of attention
What is the principle fast excitatory transmitter of the CNS?
glutamate
What is glutamate involved in?
elicits neural changes that occur with learning and development
How is glutamate involved when the CNS has been damaged?
may contribute to neuron death
glycine and GABA are (activators/inhibitors)
inhibitors
major inhibitory NT in the CNS
GABA
GABA often acts here
interneurons in the spinal cord
glycine inhibits
postsynaptic membranes, primarily in
- brainstem
- spinal cord
glycine/GABA prevent
excessive neural activity
low levels of glycine/GABA may cause
- seizures
- anxiety
- unwanted muscle contractions
Where is dopamine produced?
neurons in substantia nigra and midbrain
What does dopamine affect?
- motor activity
- cognition
- behavior
*reward and pleasure
signaling pathways that use dopamine are involved in these conditions
- Schizophrenia
- Parkinson’s
What do Schizophrenia and Parkinson’s drugs do?
- prevent dopamine from binding (decrease hallucinations, delusions, etc)
- may result in spasms
cocaine’s effect on dopamine reuptake
- prevents reuptake
- prolongs dopamine activity
- produces euphoria and “stereotypical” coked out behavior
norepinephrine is also called
noradrenaline
high levels of NE are associated with
vigilance
lowest levels of NE present during
sleep
NE in the PNS
- secreted by adrenal gland
- released by neurons in ANS
NE in CNS produced here
- brainstem nuclei
- thalamus
- hypothalamus
high levels of NE are associated with these problems
- panic disorder
- PRSD
NE acts on these regions of the brain
- cortical
- limbic
serotonin effects
- mood
- perception of pain
- arousal level
- suppresses sensory information
highest levels of serotonin during
alertness
lowest levels of serotonin during
REM sleep
low levels of serotonin associated with
depression
How do SSRIs work?
- block serotonin reuptake
- keeps in synapses longer
endogenous opioid peptides bind to
same receptors as the drug opium
opioid peptides include these
- endorphins
- enkephalins
- dynorphins
opioid peptides inhibit
CNS neurons involved in pain perception
opioid peptides are predominant here
- spinal cord
- hypothalamus
- gray matter areas in brainstem
types of channels that are directly activated
ligand gated
ligand gated channels are (ionotropic/metabotropic)
ionotropic
ligand gated channels are proteins that function as both
- receptors for NT
- ion channels
ligand gated channels open when
NT binds to receptors
glutamate and ligand gated channels
positive ions flow in and depolarize, producing EPSP
GABA and ligand gated channels
- Cl- channels
- Cl- ions diffuse into the cell
- hyperpolarize the membrane
indirect activation
g-proteins
g-protein activated channels are (ionotropic/metabotropic)
metabotropic
sequence of events when a NT binds to a g-protein
- protein changes shape
- g-protein activated
- active subunits of the protein break free and act as signaling shuttles
- subunits bind to a membrane ion channel
- ion channel changes shape and opens
- subunits become deactivated and reassociate with the receptor
