Lecture 15 Flashcards
2 types of communication occurring in neurons
Electrical (within neurons)
Chemical (between neurons)
Major excitatory NT in brain
Glutamate
Receptors used by glutamate, ionotropic or metabotropic
AMPA, kainate, NMDA
(all ionotropic)
Major inhibitory NT in brain
GABA (and glycine)
GABA receptor types
GABAa - ionotropic, fast, Cl- channel, alcohol works here
GABAb - metabotropic, slow, through neurogliaform interneurons
GABAc - ionotropic, Cl- channel
Alcohol on brain
- Biphasic (initial stimulant, then depressant)
- Activates GABAa - Cl- ions cause hyperpolarization, postsynaptic inhibition
- Layer 5 of basal dentrites damaged - lose cells and connections randomly
- Diminished cortical thickness, enlarged ventricles
Fetal Alcohol Syndrome effects
Changes in facial features, stunted growth, intellectual disability, etc.
* Almost non-existent corpus callosum
Layer 5 of basal dentrites damaged
Cholinergic receptor types (ACh)
nicotinic - ionotropic, excitarory
muscarinic - metabotropic, excitatory or inhibatory
Cholinergic pathway functions
Motor, learning + memory, (depleted in neurodegenerative disorders like Alzheimers)
Dopamine
- mesostriatal pathway (originate in midbrain, subtantia nigra/VTA), innervates striatum
- motor control
- reward, reinforcement, learning
- abnormalities = schizophrenia, addiction
Norepinephrine
-released from locus coeruleus (pons)
- project broadly
- CNS receptors all metabotropic
- mood, arousal, sexual behaviour
Serotonin
-mainly found in raphe nuclei
- project widely
- sleep, mood, anxiety, sexual arousal
Berthold - testosterone in chickens
- first hormone identified
- no testes = small, weak, don’t mount hens, aren’t aggressive
- act upon blood, then whole organism
Endocrine glands __________
release hormones that travel through bloodstream
largest - smallest hormones
protein (peptide), amines, steroids
- proteins = string of a.a.
- amine = modified a.a.
- steroid = 4 rings of carbon atoms