Synaptic Transmission at the Neuromuscular Junction and CNS Flashcards
what is the effect of the inotropic Ach (Beta 1) receptor?
muscle contraction of the heart
what is the effect of the metabotropic (M2) receptor?
decrease in heart rate via G protein complex via vagus nerve
how is synaptic communication varied in the brain?
Use of different neuronal transmitters
Presence of several different type of receptors
Activation of different down-stream pathways via these receptors
Difference in time courses of synaptic interaction
most presynaptic terminals arise from?
axons, they can form synapses on any part of a neuron
what is significant to note about the contact sites formed by the neurons?
The contact site determines the way in which the synapse is named: axodendritic, axosomatic, axoaxonic
in the CNS, in more than 90% of all excitatory synapses, the postsynaptic site is a _____?
dendritic spine
what do the dendritic spines contain?
transmitter receptors, structural proteins, and proteins for endocytosis and glycolysis, these help with plasticity of the brain and how we remember things
what are the functions of the dendritic spines (?
increase the opportunity for a dendrite to form synapses, and also isolate (electrically or chemically) individual synapses from the rest of the cell.
the dendritic spines are generally associated with these medical conditions?
ADHD (pruning of dendritic spines) and schizophrenia (too much dendritic spine)
what is the effect of having too little dendritic spines?
delayed neuro cognitive growth
what are modulatory systems?
several systems of neurons that regulate the general excitability of the CNS
T/F, modulatory systems use the same neurotransmitter?
F, they use different neurotransmitters
what is consciousness dependent on?
1) An Intact Ascending Reticular Activating System
2) Direct Afferent Systems (raphe nucleus, locus coeruleus, parabrachialis)
what are the widespread projection systems in the nervous system that we studied in class?
reticular formation intralaminar nuclei mideline thalamic nuclei norepinephrine dopamine serotonin histamine acetylcholine
what are the pathways of dopamine, name the three?
mesostriatal, mesolimbic, and mesocortical;
for all three, it starts from the midbrain and then it diverges to the striatum, limbic structures and then the prefrontal cortex
what is significant about the target regions of dopamine?
These are the regions that mediate reinforcement or reward, and involved in psychiatric disorders
where does the nigrostriatal system project?
it projects from the substantial nigra to the caudate nucleus and putamen
where does the mesolimbic system project?
it projects from ventral tegmental area to the limbic system (including the nucleus accumbens, amygdala, and hippocampus)
where does the mesocortical system project?
it projects from the ventral tegmental area to the cortex
what type of receptors are dopamine receptors?
metabotropic
how many families of dopamine receptors are there?
two families
what are the two families of receptors?
D1-like receptors are postsynaptic, whereas D2-like receptors are pre- and postsynaptic
what is the locus coeruleus? what nt is this the target site for?
cells believed to be involved in the regulation of attention, arousal, and sleep-wake cycles, also in learning and memory, anxiety, pain, mood, and brain metabolism ; norepinephrine
what side are the D2 receptors on in terms of noradrenergic projection systems?
the presynaptic side and usually inhibitory by inhibiting release of dopamine from presynaptic site
