These hibernating squirrels could use a drink – but don’t feel thirsty – Eurasia Review

The thirteen-lined ground squirrel does not drink during hibernation, even though the systems throughout its body cry out for water.

Madeleine Junkins and colleagues now show that the squirrel suppresses the need to quench its thirst by reducing the activity of a number of neurons in highly vascularized brain structures called circumventricular organs, which act as a specialized junction between the brain, the bloodstream and the brain -Spinal fluid act.

Junkins’ study et al. helps explain how some hibernating animals ignore the strong physiological urge to search for water for months. During hibernation, squirrels alternate between periods of torpor (inactivity and suppressed metabolism) and periods of excitement between bouts (higher core temperatures and some movement in the burrow).

Although intermediate squirrels are dehydrated and sensitive to some renal and nervous system cues regulating fluid homeostasis, they are less sensitive to other hormonal thirst stimuli.

The researchers found that the basal activity of thirst neurons in the circumventricular organs decreases sharply during the hibernation months, suppressing their sensitivity to physiological thirst stimuli.