Intro. To Neur / Physio. of Neuro / Neurochemistry – Flashcards

cells of the cerebellum, neurons with the most dendritic branches

- "electrical synapses" - Allow direct ion & small molecule flow from one neuron to another, usually bidirectional

- Site of neurotransmitter release, slower form of neuronal communication - Axo-Dendritic: most common synapse - Axo-Somatic: common GABAergic synapse - Axo-Axonic: least common synapse

(Glial Cell) - structural partners at chemical synapses, capable of glutamate and K+ uptake - form contact with cerebral blood vessels

(Glial Cell) - immune cell of nervous system, capable of phagocytosis - Capable of releasing cytokines and triggering inflamation

(Glial Cell) - myelin producing cells of the CNS (Oligodendrocyte)/PNS(Schwann Cell) - Implicated in demyelinating and dysmyelinating diseases

(non-neural & non-glial cell) - wrap around vessels and are in direct contact with endothelial cells via gap junctions.

(non-neural & non-glial cell) - cells of the ventricles in the brain that have multiple cilia and move to produce CSF flow

(non-neural & non-glial cell) - composed of epithelial and endothelial cells, participate in the formulation of CSF

the point at which [K+ flow out of cell = K+ flow into cell] E K+ = (-80mV) --> rVm (resting membrane potential ~ -65mV) is closest to this E Na+ = (62mV) E Ca2+ = (123mV) E Cl- = (-65mV)

- Neurons have threshold for AP generation at -40mV --> this is determined by voltage-gated Na+ channels 1. Rising Phase: rapid depolarization (increased Na+ permeability) 2. Overshoot: depolarization to >0mV 3. Falling Phase: rapid hyperpolarization (increased K= permeability) 4. Undershoot: hyperpolarization past rVm (-65mV)

- Regions of high density of Na+ channels on axon allow for regeneration of AP --> by increasing conduction along the axon

- Na+ channel blocker (inhibits AP) --> respiratory failure & cardiac arrest - Found in puffer fish

- Na+ channel blocker (inhibits AP) --> respiratory failure & cardiac arrest - Produced by dinoflagellates

- K+ channel blocker (prolongs action potentials) - Found in venom of green mamaba

- Na+ channel blocker (inhibits AP) --> respiratory failure & cardiac arrest

- Glutamate (NT) depolarize the post-synaptic neuron - Ionotrophic glutatmate receptors have a Na+ pore which allows the depolarization, making it EASIER for the postsynaptic neuron to fire a further AP - Pre-synaptic voltage-gated Ca2+ channel cause the NT release at terminal

- GABA hyperpolarizes the post-synaptic neuron - Ionotrophic GABA receptors have a Cl- pore which allows the hyperpolarization, making it HARDER for postsynaptic neuron to fire a further AP

- autoimmune disease characterized by the production of antibodies against AchR - Symptoms include muscle weakness (due to AchR being unable to cause muscle contractions) throughout the body especially face

- autoimmune disorder characterized by the production of antibodies against voltage-gated Ca2+ channels (preventing the release of neurotransmitters) in neuromusclar junction

- released by neurons connected to voluntary muscle contraction, neurons that control heart beat, and also as NT in brain - SYNTHESIS: Acetyl-CoA + Choline = Acetylecholine + CoA - Synthesis Location: nucleus of meynert, amygdala, hippocampus, brainstem nuclei - RECEPTORS: Muscarinic, Nicotinic, Both

- Catecholamine - Present in three principle circuits (midbrain, ventral tegmental area, hypothalamus)--> control movement, psychiatric symptoms, has also been directly linked to Parkinson's, also regulates endocrine system (DA directs hypothalamus to synthesize hormones) - RECEPTORS: D1 & D5 (cerebral cortex, limbic system), D3 & D5 (hypothalamus), D1 & D2 (corpus straitum)

- Catecholamine - cell bodies of norepinephrine neurons are located in the brain stem, mainly LOCUS COERULEUS - released by sympathetic neurons in the periphery to regulate heartbeat & blood pressure - Acute stress increases the release of NE from sympathetic nerves and the ADRENAL MEDULLA - RECEPTORS: 2 types of adrenoceptors (alpha & beta): alpha2 receptors are found in neurons, blood vessels, pancreas, and smooth muscle and are coupled to INHIBITORY G-proteins (they have an inhibitory effect on NT release when bound by agonist)

Tyrosine --> L-Dopa (*affective treatment for parkinson's) --> Dopamine (DA - produced by substanstia nigra) --> Norepinephrine (NE - produced by locus coeruleus) --> Epinephrine (produced by neurons of brain stem)

- Indoleamine present in the brain, blood platlets, lining of digestive tract - Drugs that alter 5-HT synaptic levels (i.e. Fluoxetine) relieve symptoms of depression and OCD - SYNTHESIS: mainly in the Raphe Nuclei - RECEPTORS (membrane receptors are 7 trans-membrane spanning alpha-helices): Ionotrophic (channel-linked), Metabotropic (G-protein coupled), kinase-linked receptors, intracellular receptors that regulate gene transcription

- widely distributed throughout the brain and serve as building blocks of proteins - NT Glycine & GABA: inhibit the firing of neurons - GABA receptor: five subunits, two molecules of GABA activate receptor by binding to the alpha-subunit--> allowing the passage of negatively charged ions into the cytoplasm (hyperpolarization) - GLUTAMATE & ASPARTATE: act as excitatory signals(depolarization), Ketamine affects the Glutamate system - GLUTAMATE RECEPTORS: NMDA, Kainate, AMPA

- associated with pathways in brain associated by painful or tissue-damaging stimuli

- Nitric Oxide and carbon monoxide are gases and cannot be stored in any structure so they do NOT act as NT - Instead they are made by enzymes (i.e. NOS) as they are needed and released from the neurons via diffusion - these gases do NOT act on receptors, instead they diffuse into adjacent neurons and act upon chemical targets--> Nitric Oxide (NO) neurotransmission governs erection in the penis