Alpha-2 adrenergic modulation of prefrontal cortical neuronal activity related to spatial working memory in monkeys.
The effects of systemically administered or iontophoretically applied clonidine (alpha-2 adrenergic agonist) and iontophoretically applied yohimbine (alpha-2 adrenergic antagonist) were examined on prefrontal cortical (PFC) neurons related to spatial working memory (SWM). Systemically administered clonidine (0.04 mg/kg) enhanced SWM-related PFC neuronal activity by 32.5 +/- 14.5%, (mean +/- SD; n = 25 neurons). The facilitatory effect of clonidine was antagonized by iontophoretically applied yohimbine. Iontophoretically applied clonidine enhanced SWM-related PFC neuronal activity by 38.2 +/- 18.6%, (n = 13 neurons), whereas similarly applied yohimbine suppressed it by 34.4 +/- 17.8% (n = 28 neurons). These results indicate that: a) systemically administered clonidine can facilitate SWM-related PFC neuronal activity through actions at alpha-2 adrenoceptors in the PFC; and b) conversely, blockade by yohimbine of alpha-2 adrenoceptors in the PFC suppresses SWM-related neuronal activity. The present study provides neurophysiological evidence that alpha-2 adrenoceptors in the PFC are involved in the cellular mechanisms underlying working memory.
Li
B M
BM
Key Laboratory of Neurobiology, Shanghai Institute of Physiology, Chinese Academy of Sciences, People's Republic of China.
Mao
Z M
ZM
Wang
M
M
Mei
Z T
ZT
D000200:Action Potentials / Q000502:physiology; D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000818:Animals; D001931:Brain Mapping; D003000:Clonidine / Q000494:pharmacology; D004585:Electrooculography; D005133:Eye Movements / Q000502:physiology; D005260:Female; D015918:Infusion Pumps, Implantable; D008253:Macaca mulatta; D008568:Memory / Q000187:drug effects* / Q000502:physiology*; D009474:Neurons / Q000187:drug effects* / Q000502:physiology*; D017397:Prefrontal Cortex / Q000166:cytology / Q000187:drug effects* / Q000502:physiology*; D011597:Psychomotor Performance / Q000187:drug effects; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology; D018341:Receptors, Adrenergic, alpha-2 / Q000502:physiology*; D013028:Space Perception / Q000187:drug effects / Q000502:physiology; D015016:Yohimbine / Q000494:pharmacology
D000316:Adrenergic alpha-Agonists; D000317:Adrenergic alpha-Antagonists; D018341:Receptors, Adrenergic, alpha-2; D015016:Yohimbine; D003000:Clonidine