# PHOTOPERIOD, BEHAVIOR AND BRAIN FUNCTION

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA BERKELEY · 1994 · $225,009

## Abstract

The main aims of the proposed work are to specify the neural and endocrine
bases for seasonal rhythms in physiology, behavior and structure of
mammals. The model species to be studied is the Siberian hamster,
Phodopus sungorus. A model system has been developed in which a single long
day stimulates reproductive development in hamsters housed in short
photoperiods. This renders feasible a new set of experiments with specific
aims that include; 1) determining whether the time of weaning constitutes a
special sensitive period for induction of reproductive development by
light; 2) assessing whether puberty is associated with a permanent
reduction in responsiveness to light; 3) establishing the roles of the
pineal hormone melatonin and the suprachiasmatic nuclei in sustaining
reproductive development once a long-day signal has been received by the
neuroendocrine axis; 4) determining the duration of the daily
photosensitive phase and how it is affected by prior photoperiodic history;
5) describing the postnatal development of responsiveness to melatonin in
the neuroendocrine-gonadal axis; 6) determining the long-term behavioral
consequences of a single long day given at weaning, and 7) describing the
role of the circadian system and prior photoperiodic history in
neurochemical mediation of seasonal cycles.  Many human dysfunctions occur
only at certain seasons. By specifying the role of the neuroendocrine
system and day length in seasonality, we may establish principles that will
permit better understanding and control of human behavior.

## Key facts

- **NIH application ID:** 2194801
- **Project number:** 5R01HD002982-28
- **Recipient organization:** UNIVERSITY OF CALIFORNIA BERKELEY
- **SAM.gov UEI:** GS3YEVSS12N6
- **Principal Investigator:** IRVING ZUCKER
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1994
- **Award amount:** $225,009
- **Award type:** 5
- **Project period:** 1978-08-01 → 1996-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/2194801

## Citation

> US National Institutes of Health, RePORTER application 2194801, PHOTOPERIOD, BEHAVIOR AND BRAIN FUNCTION (5R01HD002982-28). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/2194801. Licensed CC0.

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