Neuroanatomical distribution and function of the vasopressin V1B receptor in the rat brain deciphered using specific fluorescent ligands.

摘要: It is now accepted that vasopressin, through V1A/V1B receptors, centrally regulates cognitive functions such as memory, affiliation, stress, fear and depression. However, the respective roles of these receptor isoforms their contribution to stress-related pathologies remain uncertain. The development new therapeutic treatments requires a precise knowledge distribution receptors within brain, which has been so far hampered by lack selective V1B markers. In present study, we have determined pharmacological properties three potent rat fluorescent ligands demonstrated they constitute valuable tools for simultaneous visualization activation native in living brain tissue. Thus, d[Leu4,Lys-Alexa 647)8]VP (analogue 3), compound with best affinity-selectivity/fluorescence ratio emerged most promising. regions concerned stress hippocampus, olfactory bulbs, cortex amygdala display highest labelling analogue 3. hippocampus CA2, are located on glutamatergic, not GABAergic neurones, absent from astrocytes. Using AVP-EGFP rats, demonstrate presence autoreceptors AVP-secreting neurones only hypothalamus, but also sparsely hippocampus. Finally, using both electrophysiology ERK phosphorylation, show 3-induced situ. This will help analyse expression functionality contribute further explore AVPergic circuitry normal pathological conditions.