Neurotransmission In Cns

Front 1

List the major neurotransmitters in the brain

Back 1

b. Norepinephrine
c. Dopamine
d. Serotonin
e. Acetylcholine
f. Glycine
g. Gamma-aminobutyric acid (GABA)
h. Glutamate
i. Opioid peptides
j. Leptin
k. Other peptides normally associated with the gut and endocrine tissues are also present in the CNS: vasoactive intestinal peptide, cholecystokinin, thryotropin releasing hormone, and somatostatin.
l. Endocannabinoids

Front 2

where is norepineprhine localized

Back 2

i. Cell bodies found in pons (locus ceruleus) and midbrain, and project diffusely to virtually all regions of the cerebral cortex and limbic system.

Front 3

what is norepinephrine associated with?

Back 3

ii. Noradrenergic neurons in the limbic system are thought to be a major target of antidepressent drugs. These drugs increase the amount of NE in the synapse.

Front 4

what are the three major pathways that utililze dopamine

Back 4

i. Three ascending pathways of importance: nigrostriatal (extrapyramidal motor control), tuberoinfundibular (neuroendocrine regulation), and mesolimbic (emotions, reward system).

Front 5

where are some areas that are affected by disases that invovle dopamine

Back 5

ii. Nigrostriatal: Parkinson’s disease caused by selective cell death; MPTP Frozen Man Syndrome caused by toxin being transported into neurons.
iii. Substantia nigra to limbic system and widespread cortex: addiction and behavioral disorders
iv. Arcuate nucleus of the hypothalamus to anterior pituitary (via portal veins): inhibits prolactin secretion

Front 6

where is serotonin localized

Back 6

i. Diffuse pathways ascend to the cerebral cortex and limbic system from the midline tegmentum (raphe nucleus in the pons).

Front 7

what is serotonin associated with

Back 7

ii. Antipsycotics and antidepressants broadly target the serotonergic system to varying extents. Drugs used to treat mood disorders, migraine pain, chemo-induced emesis. LSD activates 5-HT1 and 2 receptors.

Front 8

what are some conditions that occur due to issues with acetylocholine in the neruomuscular junction

Back 8

(nerve gases/insecticides), myasthenia gravis, and botulism toxin (disrupts Ach release  flaccid paralysis).

Front 9

what are some conditions that arise due to acetylcholine issues in the brain

Back 9

iii. The pathway involving the basal forebrain to widespread cortex is affected by Alzheimer’s disease (atrophy of cholinergic neurons) and Autosomal dominant frontal lobe epilepsy (mutations in CNS Ach receptor).
iv. Atrophy of interneurons in the striatum are implicated in Parkinson’s disease (tremor).

Front 10

important info on glycine?

Back 10

i. Cell bodies found in spinal cord.
ii. The poison strychnine induces convulsion by blocking the glycine receptor (glycine is an inhibitory neurotransmitter).

Front 11

where is GABA localized

Back 11

in cerebellum, cerebral cortex, and limbic system.

Front 12

what is the action of GABA

Back 12

ii. Major inhibitory NT in the brain. Sedative hypnotics act by facilitating the action of GABA. Barbituates in high doses can directly activate the GABA receptor resulting in profound respiratory depression and CV collapse.

Front 13

where is glutamate localized

Back 13

i. Widely distributed in the CNS; receptors are NMDA and non-NMDA

Front 14

what happens when you block Glutamate

Back 14

ii. The tranquilizing/anesthetic agents ketamine and phencyclidine block the NMDA receptor. These drugs can produce disordered thinking similar to schizophrenia.

Front 15

where is leptin localized

Back 15

i. Synthesized and secreted in adipose tissue. Receptors are found in the CNS, especially the ventromedial hypothalamus.

Front 16

what is leptin associated with

Back 16

ii. Leptin insensitivity may be a cause of obesity.

Front 17

what is info for endocannabinoids

Back 17

i. Cannabinoid receptor (CB1) is widely distributed in the CNS. The ligands are thought to be brain lipids. They are secreted from the postsynaptic neuron, bind the CB1 receptor on the presynaptic neuron and inhibit NT release. Activation of these receptors affects memory, cognition, and pain perception.

Front 18

discribe Voltage-gated ion channels

Back 18

open in response to changes in transmembrane potential. This is how action potentials are propagated along nerve cells. These channels are the targets of antiseizure drugs.

Front 19

discribe ligand gated channels

Back 19

channel opens in response to the binding of a chemical to a specific receptor. This is the general mechanism of synaptic transmission, and is the site of action of most drugs that act in the CNS.

Front 20

4. Identify the factors that determine whether a drug will gain access to the central nervous system.

Back 20

a. The entry of drugs into the CNS is restricted by the blood-brain barrier, the anatomic basis of which is tight junctions between endothelial cells in the capillaries of the brain.
b. The concentration of drugs in the CNS is enhanced by: lipophilic drugs, transport into the CNS by transporters that normally transport nutrients into the CNS, and by inflammation of the meninges or brain.
c. P-glycoprotein is a nonspecific transporter that actively transports drugs out of the brain into the blood.