Open Access. Powered by Scholars. Published by Universities.®

Social and Behavioral Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 2 of 2

Full-Text Articles in Social and Behavioral Sciences

Distinct Retinohypothalamic Innervation Patterns Predict The Developmental Emergence Of Species-Typical Circadian Phase Preference In Nocturnal Norway Rats And Diurnal Nile Grass Rats, William D. Todd, Andrew J. Gall, Joshua A. Weiner, Mark S. Blumberg Oct 2012

Distinct Retinohypothalamic Innervation Patterns Predict The Developmental Emergence Of Species-Typical Circadian Phase Preference In Nocturnal Norway Rats And Diurnal Nile Grass Rats, William D. Todd, Andrew J. Gall, Joshua A. Weiner, Mark S. Blumberg

Faculty Publications

How does the brain develop differently to support nocturnality in some mammals, but diurnality in others? To answer this question, one might look to the suprachiasmatic nucleus (SCN), which is entrained by light via the retinohypothalamic tract (RHT). However, because the SCN is more active during the day in all mammals studied thus far, it alone cannot determine circadian phase preference. In adult Norway rats (Rattus norvegicus), which are nocturnal, the RHT also projects to the ventral subparaventricular zone (vSPVZ), an adjacent region that expresses an in-phase pattern of SCN-vSPVZ neuronal activity. In contrast, in adult Nile grass rats (Arvicanthis …


Development Of Scn Connectivity And The Circadian Control Of Arousal: A Diminishing Role For Humoral Factors?, Andrew J. Gall, William D. Todd, Mark S. Blumberg Sep 2012

Development Of Scn Connectivity And The Circadian Control Of Arousal: A Diminishing Role For Humoral Factors?, Andrew J. Gall, William D. Todd, Mark S. Blumberg

Faculty Publications

The suprachiasmatic nucleus (SCN) is part of a wake-promoting circuit comprising the dorsomedial hypothalamus (DMH) and locus coeruleus (LC). Although widely considered a "master clock," the SCN of adult rats is also sensitive to feedback regarding an animal's behavioral state. Interestingly, in rats at postnatal day (P)2, repeated arousing stimulation does not increase neural activation in the SCN, despite doing so in the LC and DMH. Here we show that, by P8, the SCN is activated by arousing stimulation and that selective destruction of LC terminals with DSP-4 blocks this activational effect. We next show that bidirectional projections among the …