Feeding differences in pubertal and aged golden hamsters (Mesocricetus auratus) are related to specific cerebral expression pattern of histamine subtype 3 receptor

Abstract

The hibernating golden hamster (Mesocricetus auratus) is becoming a useful rodent model to study the neurophysiological role of some neuromediators on vital behaviors such as sleep and thermoregulation. Recent works have shown that the histamine neuroreceptor subtypes (H-sub(1-3)R) are able to modulate such behaviors. Here, specific subtype(s) and cerebral nuclei that were actively operating on feeding behaviors in pubertal and adult hamsters were identified. Of the subtypes assessed, H-sub-3R antagonist (thioperamide) provoked significant (p < .001) changes in behavior (very low total food and water intake) in adults, whereas it did not significantly modify these behaviors in pubertals. The H-sub-3R antagonist's role seemed to be related to elevated amounts of stress-induced damaged neurons displaying, mainly, shrunken crenated cell membranes and altered synaptic processes in limbic areas such as amygdala, cortex, and hippocampus. At the transcription level, an evident expression pattern of H-sub-3R messenger RNA appeared in pubertals, especially in neurons of the cortex and hippocampus, whereas the same trend was featured in amygdalar areas of hibernating adult hamsters, suggesting early H-sub-3R regulatory activities, at least in limbic sites of this rodent model.