Alterations in monoamine neurotransmitters and dendritic spine densities at the medial preoptic area after sleep deprivation.
The experiments were conducted on 24 adult male Wistar rats to find out the alterations in the levels of monoamines and dendritic spine densities in the medial preoptic area and cortex after total sleep deprivation. Noradrenaline was reduced in the medial preoptic area, though there was no significant change in the cortex. Dopamine and serotonin were decreased both in the medial preoptic area and in the cortex. Dendritic spine counts in the medial preoptic area and the motor cortex were increased after total sleep deprivation. Enhanced release of the monoamines and their subsequent breakdown during sleep deprivation could be responsible for the decreased levels of the transmitters. An increase in synaptic activity, resulting in the enhanced release of the transmitters, might be responsible for the increased spine density after total sleep deprivation. Localized changes in noradrenaline levels at the medial preoptic area suggest its involvement in sleep genesis and maintenance, though its possible contribution to other functions like thermoregulation and reproduction cannot be ruled out. As the available literature does not indicate a role for serotonin and dopamine at the medial preoptic area in sleep regulation, these changes may represent their participation in non-sleep functions.
Ramesh
V
V
Department of Physiology, All India Institute of Medical Sciences, New Delhi 110 029, India.
Lakshmana
M K
MK
S
B
B
Rao
S
S
Raju
T R
TR
Kumar
V M
VM
D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000818:Animals; D015306:Biogenic Monoamines / Q000378:metabolism*; D003712:Dendrites / Q000502:physiology*; D004298:Dopamine / Q000378:metabolism; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D008297:Male; D009044:Motor Cortex / Q000166:cytology / Q000378:metabolism; D009638:Norepinephrine / Q000378:metabolism; D011301:Preoptic Area / Q000166:cytology / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000378:metabolism; D012892:Sleep Deprivation
D015306:Biogenic Monoamines; D015102:3,4-Dihydroxyphenylacetic Acid; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D004298:Dopamine; D009638:Norepinephrine