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T Cianci

Publications and source records attributed to T Cianci.

34 records · Page 2Linked to original sources
PubMed1981

Respiratory effects of preoptic-anterior hypothalamic electrical stimulation during sleep in cats.

The respiratory effects of preoptic-anterior hypothalamic (PO-AH) and vagal repetitive electrical stimulation (RES) were studied in unrestrained cats during sleep. PO-AH RES influenced breathing consistently during synchronized sleep but only occasionally during desynchronized sleep. Induction of desynchronized sleep by PO-AH RES was also observed. The respiratory effects of PO-AH RES on one side were enhanced by concomitant PO-AH warming on the other side during synchronized sleep but not during desynchronized sleep. Breathing was affected by vagal RES during both sleep stages, although an increase in threshold and in variability of respiratory responses was apparent during the latter sleep stage. The results show that PO-AH unresponsiveness during desynchronized sleep is nonspecific.

Animals↗
PubMed1980

Cutaneous vasomotion during REM sleep in the rabbit's ear, after alpha-receptor blockade.

Cutaneous vasoconstriction in the rabbit's ear during REM sleep in a warm environment is not abolished by alpha-receptor blockade (phenoxybenzamine 6 mg/kg i.v.), thus confirming that the vasomotor response during REM sleep is independent of the activity of circulating catecholamines. The decrease in cardiac output during REM sleep may be responsible for the slight fall in transmural pressure which underlies cutaneous ear vasoconstriction during REM sleep.

Adrenergic alpha-Antagonists↗
PubMed1980

Emotional hypothermia induced by classical aversive conditioning in the rabbit.

The CS induces a stereotyped change in all the autonomic variables studied: Ts decreases, RF and Thy increase. Within an average 300 sec from the CS a new steady state is reached, characterized by a lower Thy and a higher RF compared to the respective control values before the CS. Throughout the session the CS sequence determine a significant decrease in Thy which is analogous in our opinion with the "emotional hypothermia" induced in rabbits and rats by restraint.

Animals↗
PubMed1980

Vasomotor adjustments in the rabbit's ear during REM sleep.

In the rabbit auricolar vessels constrict during REM sleep at high ambient temperatures (26-30 degrees C) and dilate a low ambient temperatures (0-5 degrees C). These opposite vasomotor adjustments during REM sleep are inconsistent with the logic of a thermoregulatory mechanism; they can only be understood as new equilibria of the vessels calibre to the drop in sympathetic vasoconstrictor tone and fall in transmural pressure during REM sleep. By cutting the sympathetic nerve supply to the ear we can rule out the neurogenic origin of ear vasoconstriction during REM sleep.

Animals↗
PubMed1980

Quantitative analysis of short term deprivation and recovery of desynchronized sleep in cats.

A quantitative analysis of desynchronized sleep (DS) deprivation (exposure to low ambient temperature) and recovery was carried out in unrestrained cats. The results show that: (1) the circadian obligate quota of DS is precisely regulated by a control mechanism paying by the 24th h the DS debt induced by up to 14 h of total DS deprivation, if recovery occurs during the rest phase of circadian photoperiodicity (CP); (2) during static rebound DS hourly duration is increased by 40 +/- 4 sec/h of total deprivation (mean and S.E.) and there is a statistically significant increase in the hourly frequency and in the duration of DS episodes, with respect to control values; (3) the hourly obligate and facultative quotas of DS amount to 409 +/- 82 and 229 +/- 140 sec/h (mean and S.D.), respectively. (4) preoptic heating during deprivation at low ambient temperature decreases the DS static rebound during recovery at control ambient temperature by an amount corresponding to the cumulative duration of DS episodes elicited by the preoptic treatment; (5) preoptic temperature decreases the more markedly the shorter the duration of exposure to low ambient temperature and regains control values the sooner the smaller the DS debt incurred during deprivation; (6) DS debt cumulation is a continuous process which develops at a steady rate during day and night, whereas DS debt payment is a discontinuous process (ultradian rhythm of DS) which develops at a variable rate depending on the DS debt and on the phase of CP.

Animals↗
PubMed1977

Absence of thermoregulatory vasomotor responses during fast wave sleep in cats.

The skin temperature of the pinna was recorded in unrestrained cats sleeping at different ambient temperatures. The results show that during fast wave sleep vasomotion is inconsistent with homeothermic regulation as ear skin temperature increases and decreases at low and high ambient temperatures, respectively. The effects of preoptic heating during slow wave and fast wave sleep reveal that a depression of the responsiveness of hypothalamic thermoceptive structures underlies the absence of thermoregulatory vasomotor responses during fast wave sleep.

Animals↗
PubMed1975

Hypothalamic temperature during the sleep cycle at different ambient temperatures.

Hypothalamic temperature during complete and incomplete sleep cycles (slow wave sleep followed by fast wave sleep and slow wave sleep followed by arousal, respectively) has been studied in freely moving cats at 20 degrees C and 0 degrees C ambient temperatures. The results show that sleep and thermoregulatory processes interact and, at 0 degrees C ambient temperature, become mutally exclusive. The occurrence of fast wave sleep is related to an opptimum range of hypothalamic temperatures which is specific in each enviromental conditions.

Animals↗