Temperature components of sleep and wakefulness induced by an activation of cholinergic receptors of the ventrolateral preoptic area in pigeons

T.G. Komarova, I.V. Ekimova

Sechenov Institute of evolutionary and biochemistry, RAS, St. Petersburg, Russia

 

Температурные компоненты сна и бодрствования при активации холинергических рецепторов вентролатеральной преоптической области гипоталамуса у голубей.

Т.Г. Комарова, И.В. Екимова

Институт эволюционной физиологии и биохимии им. И.М.Сеченова, РАН,

Санкт-Петербург, Россия

 

 

It is well know that in many avian species and mammals sleep-wake cycle plays a key role in the regulation of the temperature homeostasis [Pastukhov, 1998-2002, Parmeggiani, 2003]. In most cases non-rapid-eye-movement (NREM) sleep contributes to a development of peripheral vasodilatation, decrease in the contractile activity of muscles and brain temperature. Rapid-eye-movement (REM) sleep and wakefulness are found to participate in the temperature regulation in the opposite direction. As determined in previous studies, activation of muscarine (М-) cholinergic receptors located into the ventrolateral preoptic area (cluster VLPO) of hypothalamus results in an increase in wakefulness and decrease in REM and NREM sleep whereas activation of nicotine (N-) cholinergic receptors of the VLPA is responsible for contrary effects [Ekimova, Komarova, 2004]. These data led us to examine whether temperature characteristics of NREM and wakefulness during activation of N- or M-receptors of the VLPO correspond to those observed under natural condition. Pigeons (Columba livia) were prepared with electrooculogram (EOG), cortical electroencephalogram (EEG), electromyogram (EMG) electrodes, guide cannulae and minithermistors for measuring brain and leg skin (to assess peripheral vasomotor response) temperature. All electrophysiological parameters were continuously recorded, processed, and stored using a computer system permitting determine a contribution each state of sleep-wake cycle to changes in temperatures. During wakefulness administration of saline into the VLPO caused an increase in brain temperature, a development of peripheral vasoconstriction and the opposite effect was observed during NREM sleep. During NREM sleep, as well as control, activation of N-cholinoreceptors (nicotine, 0.3 mkg/0.2 mkl) of the VLPA resulted in a decrease in brain temperature but in contrast to control it was responsible for development of peripheral vasoconstriction. Wakefulness stimulated by activation M- cholinergic receptors of the VLPO (arecoline, 0.6 mkg/0.2 mkl) made contribution to an increase in brain temperature. Unlike control, vasodilatation was identified during this wakefulness.

Data obtained show that not all temperature parameters of sleep and wakefulness induced by activation of cholinergic receptors located into the VLPO agree with those observed under natural condition.

 The study was supported by the Program of DBS of RAS “Integrative mechanisms of wakefulness-sleep cycle regulation”.

 

Сведение об авторе

Комарова Татьяна Геннадьевна, год рожд. 1982

Аспирант 1 года обучения, Институт эволюционной физиологии им. И.М. Сеченова, РАН

Адрес – Санкт-Петербург, пр. Мориса Тореза, 38/2, 175

e-mail – tata-komarova@mail.ru