Changes in vasoactive intestinal peptide and arginine vasopressin expression in the suprachiasmatic nucleus of the rat brain following footshock stress

Abstract

The neuropeptides, arginine vasopressin (AVP) and vasoactive intestinal polypeptide (VIP) are synthesized by neurons of the suprachiasmatic nucleus (SCN) of the hypothalamus and are important regulators of SCN function. Previous studies have demonstrated that acute exposure to stressors can disrupt circadian activity rhythms, suggesting the possibility of stress-related alterations in the expression of these neuropeptides within SCN neurons. In this study, we examined the effect of intermittent footshock stress on AVP mRNA and heterogeneous nuclear RNA (hnRNA) and VIP mRNA expression in neurons of the SCN. Young adult male Sprague/Dawley rats were subjected to 15 seconds of scrambled intermittent footshock (0.50 mA pulses, 1 pulse/second, 300 msec) every 5 minutes for 30 minutes. Animals were sacrificed 75 or 135 min after the onset of stress and brains examined for AVP mRNA and hnRNA, and VIP mRNA using in situ hybridization. Footshock stress increased AVP hnRNA levels at the 75 min timepoint whereas AVP mRNA was elevated at both the 75 and 135 min. timepoints. In contrast, footshock stress decreased the number of cells expressing VIP mRNA in the SCN without changing hybridization level per cell. These data indicate that the disruptive effect of stress on activity rhythms correlate with alterations in the expression of regulatory peptides within the SCN.

Expression of Circadian Neuropeptides in the Hypothalamus of Adult Mice is Affected by Postnatal Light Experience

“…Because all mice were entrained to 24‐h LD cycles before sacrifice, we consider that the differences observed between the groups reflect a long‐lasting effect of early light experience. Changes in AVP and VIP expression in the hypothalamus are associated with various physiological states and disorders, such as stress (47), depression (48) and hypertension (49) and, in some cases, alterations in the SCN are considered to precede the development of the disease. The results obtained in the present study are thus beginning to uncover the possibility that early light experience may not only have effects at the level of locomotor activity rhythm, but may also have effects on neuroendocrine systems.…”

Binge-pattern alcohol exposure during puberty induces sexually dimorphic changes in genes regulating the HPA axis

“…Correlative studies have demonstrated that over 50% of patients with alcohol dependency also have anxiety-related or depression-related psychiatric disorders (13), and these types of disorders are often associated with an abnormal stress response. Interestingly, women alcoholics have a higher incidence of clinically diagnosed anxiety disorders compared with men alcoholics (19,59), possibly because of the inherent sex differences in the stress responses of the HPA axis (3,25). Furthermore, repeated episodes of acute EtOH exposure increased anxiety behaviors in peripubertal animals, as measured by increased latency to explore a novel object in the retention-based passive avoidance task (38).…”

Erken Yavru Kayıplarının Sıçanlardaki Annelik Davranışına ve Sonraki Yavrulara Etkileri: Bebek Kaybının Hayvan Çalışması Modeli

“…might be better inquired by the inclusion of 'bio-communicators', as termed by Tozuka et al, in the study design (37). Nuclear factor kappa B, which is suggested to play a regulatory role in prenatal stress-induced cognitive impairment, maternal vasoactive intestinal peptide, ghrelin, and oxytocin, known to be related to emotional stress in the mother rat and affecting the neural development of offspring as well as Protein Kinase C beta1 in the hippocampus resulting from prenatal restraint stress suggested to play an important role in the impairment of learning and memory abilities of offspring could be examples for further research (34,38,39). Additionally, measurement of hippocampal long-term potentiation is considered to be a reliable indicator of the direction of neurophysiologic changes underlying learning and memory induced by maternal stress of different intensities (35).…”