23. CIRCADIAN RHYTHM, SLEEP/WAKE CYCLE; NEUROANATOMY OF RESTING STATE AND ACTIVATION Flashcards
What is The principle of the control of circadian (daily) rhythms?
„Glomerular filtration rate and tubular reabsorption/secretion peak during the active phase and decline during the inactive phase.”
What is The pacemaker of the human body?
Suprachiasmatic nucleus (SCN)
Name of this area
Anterior hypothalamic region
Identify this nucleus
Suprachiasmatic nucleus (SCN)
Neuronal inputs to the hypothalamus
-> Identify
Retino-hypo-thalamic fibers
Origin of the retino-hypothalamo pathway
Photoreception is not
confined to rods (red) and cones (green) but is also accomplished by a subset of intrinsically photosensitive retinal ganglion cells (yellow), the so-called circadian photoreceptors, that employ melanopsin as a photopigment and give rise
to the retinohypothalamic tract.
Name Neuronal connections of the suprachiasmatic nucleus (SCN) - 2
GnRH: gonadotropin releasing hormone cells
MPOA: medial preoptic nucleus
CRH: corticotropin releasing hormone cells
dPVN: dorsal subdivision of the paraventrocular
hypothalamic nucleus (PVN)
sPVN: subventricular subdivision of the PVN
DMH: dorsomedial hypothalamic nucleus
PVT: paraventricular thalamic nucleus
Name Neuronal connections of the suprachiasmatic nucleus (SCN) (part 1)
- Glu: Glutamate
- GABA: Gamma aminobutyric acid
- VIP: Vasoactive intestinal polypeptide
- IGL: Intergeniculate leaf nucleus
Circadian regulation of cortisol secretion from the adrenal gland (Adr)
-> Name the structures involved
CRH: corticotropin releasing hormone
ACTH: adrenocorticotropin Adr: adrenal gland
IML: intermediolateral cell column of the spinal cord (sympathetic premotor neurons)
PVN: paraventricular hypothalamic nucleus
SCN: suprachiasmatic nucleus
Make a schematic diagram of Circadian regulation of cortisol secretion from the adrenal gland (Adr)
One output of SCN is the pineal gland (PIN), from which ____ provides a negative feedback
melatonin
One output of SCN is the pineal gland (PIN), from which melatonin provides a negative feedback
-> identify
- RET: retina
- RHT: retino-hypothalamic tract
- MEL: melatonin
- NA: noradrenalin
- IML: intermediolateral cell column of the spinal cord (sympathetic premotor neurons)
- PVH: paraventricular hypothalamic nucleus
- GCS: superior cervical ganglion
Definition / characteristics of sleep
- Decreased motor activity
- Stereotyped posture
- Refreshing, fatigue-reducing effect
- Daily rhythmicity
- Rebound effect
- Changes in brain electrical potentials
- Increase in stimulus threshold
- Relatively easy to wake up
Phenomenologic explanation of motivation to sleep
-> S, C, S-C??
S: Homeostatic drive to sleep (e.g. a sleep substance)
C: Circadian drive to be awake
S-C shows how sleepy we feel.
Phenomenologic explanation of motivation to sleep
-> What does the schematics explains?
- Daily rhythm of sleep;
- Effects of sleep deprivation: - Why we are less sleepy in the morning than at night; - Why we sleep more the following night (rebound effect) but less than 2 times more.
Sleep stages based on electroencephalogram (EEG)
REM sleep: rapid eye movement of paradoxical sleep
Stage 4: slow wave sleep (SWS)