Chapter Six: Neurotransmitter and Neuropeptide Control

Question 1

4 ways neurotransmitters regulate hypothalamic hormones

Answer 1

1. Through a synapse in a neural pathway carrying sensory input or input from other brain regions
2. A direct synapse of axons from extra-hypothalamic neurons to neuroendocrine cells, on cell body or dendrite
3. A direct synapse on axons of the neurosecretory cell
4. Neurotransmitters can be released into hypophyseal portal veins and act directly on the pituitary gland

Question 2

Production of cortisol is regulated by what neurotransmitters

Answer 2

Opiods, endocannabinoids, ghrelin, interleukins

Question 3

Pulsatile secretion of ACTH and cortisol

Answer 3

Cortisol and ACTH released at the end of the sleep cycle

Controlled by circadian rhythms (SCN)

Diurnal

ACTH is released first, then ACTH - typically cooccur

Question 4

GnRH influenced by

Answer 4

Glutamate, norepinepherine, GABA and CRH

Question 5

GH regulation

Answer 5

Auto regulated by somatostatin and GHRH

Question 6

Oxytocin and vasopressin regulation

Answer 6

Stimulated by NE, Glu, ACh

Inhibited by GABA, opiods, cannabinoids, somatostatin

Question 7

GABA and Glutamate

Answer 7

GABA inhibits most pituitary hormones

Glutamate excites most pituitary hormones

Question 8

Electrophysiology

Answer 8

Electrode placed in the arcuate nucleus where GnRH axons terminate

Spikes = action potentials and are typically correlated with the release of a hormones

Question 9

Electrophysiology rat example

Answer 9

High frequency burst of oxytocing and then milk ejection

Question 10

Psychotropic drugs

Answer 10

Drugs alter NTs which control hormones

Hormones also change with psychoactive drugs

Antipsychotics lead to prolactin

Antidepressants modulate GH and ACTH

L-Dopa leads to decreased prolactin and increased GH

Question 11

Problems using drugs to study NT effects in hormone release

Answer 11

1. Different drugs with the same action may cause different neuroendocrine effects by binding to diff receptors
2. Diff doses may have diff effects
3. Diff drug administration methods may result in different effects on hormone release

Question 12

Astrocyte facts

Answer 12

Located near neurons

Provide energy for neurons

Remove NTs from the synapse

Have receptors for NTs