Flashcards in Lecture 47: Hypothalamus Deck (26):
Hypothalamus regulates (6)
Homeostasis, temperature, hunger/thirst, emotional states, circadian rhythms/sleep/wake, reproduction
Preoptic area and anterior hypothalamus functions (4)
Thermoregulation (fever is generated here), fluid/electrolyte balance, sexual behavior, sleep!
The ventrolateral preoptic area is crucial for...
Suprachiasmic nucleus is important for...this is based on what cycle?
Circadian rhythms; light/dark cycle
Feeding/body weight via NPY, AgRP, alphaMSH; neuroendocrine via DA (prolactin), GHRH (growth hormone)
Where do we find magnocellular neurons? What do they do?
Paraventricular and supraoptic nuclei; make oxytocin and vasopression and project directly to the posterior pituitary
Where do we find parvocellular neurons? What do they do?
Paraventricular nucleus; make "releasing factors" to influence the anterior pituitary: CRF, TRF, GnRF
Medial hypothalamus (feeding)
Satiety center (reduces feeding)
Lateral hypothalamus (feeding + 1 function)
Activates feeding and sleep-wakefulness (makes Orexin)
Ventromedial hypothalamus (feeding + 2 functions)
Reduces feeding; thermoregulation and sexual functions
What is the sole source of histamine in the brain?
Most important brain inputs from cortex to hypothalamus (2)
Inhibitory from hippocampus and excitatory from amygdala
ANS inputs to hypothalamus (2)
Nucleus of the solitary tract and reticular formation
ANS outputs from hypothalamus
Medulla (parasymp = vagal nuclei) and spinal cord (preganglionic sympa = intermediolateral nucleus)
Suprachiasmatic nucleus is innervated by the...where does it send output? Then where? What does light do?
Optic nerve; superior cervical ganglion (sympa); activates pineal gland to release melatonin; TURNS OFF melatonin synthesis
All of the neuroendocrine and pre-autonomic neurons of the hypothalamus are innervated by what nucleus?
T/F: The molecular circadian clock is only located in the SCN
False: these molecules are present all over the body, it is just controlled by light in the SCN (hence, circdian rhythms)
Orexin is expressed solely in the...promotes...is also...
Lateral hypothalamus; wakefulness, arousal, reward; pro-feeding
Name two TF and one gene that regulates our circadian rhythms and describe
TF: Clock+Bmal and Period; Period inhibits Clock+Bmal and then neg feedbacks to inhibit itself; Period protein is degraded w/ a 24 hour cycle
Sleep appears to be essential for...
Sleep is thought to be initiated by...NT? Turns off (nuclei)?
Ventrolateral preoptic area (GABA); orexin (LH) and histamine (TMN)
Orexin and histamine usually project to...What do these usually do? Then what?
Monoamine and cholinergic nerve cells that provide major activation to thalamus; intrinsic circuits = large waves
Describe REM (NT?) and what turns this on? NT? Why does this not happen during the day?
Series of brainstem cholinergic cells (REM-on) become activated and trigger sensory input into thalamus (REM waves); LOSS of REM-off cells (monoamine); REM-off cells are normally activated by Orexin
What chemical builds during wakefulness that might trigger the VLPO?