The transition to reproductive senescence is characterized by increase in A6 and AVPV neuron activity with attenuation of noradrenaline content.

During the course of life, cyclic females face a state of midlife transition that occurs in a fully functioning neurological system, and results in reproductive senescence. The authors' hypothesis was that changes in the activity noradrenergic neurons may be one of the factors involved in this phenomenon. The aim of this study was to investigate the activity of the neurons in the anteroventral periventricular nucleus (AVPV) and locus coeruleus (LC), to analyze their role in determining reproductive senescence.