# DEVELOPMENT OF CIRCADIAN RHYTHMS

> **NIH NIH R01** · NORTHEASTERN UNIVERSITY · 1994 · $170,199

## Abstract

The behavior and physiology of animals and humans are regulated by
endogenously generated 24-hour (circadian) rhythms. The suprachiasmatic
nucleus (SCN) of the hypothalamus contains a circadian pacemaker that is
essential for the regulation of circadian rhythms. Disruptions of
circadian rhythms affect the health and well-being of millions of people
and result from external disturbances such as shift-work and jet-lag and
from constitutional variation of known (e.g. blindness) and unknown
causes. A possible source of variation is the environment during
development. The proposed project will study the development of circadian
rhythms and the development of the SCN in an established animal model for
circadian rhythms research, the hamster. The long-term goals of the
project are: l. To understand the relationship between SCN organization
and the regulation of circadian rhythms by examining this relationship
during development, 2. To understand the mechanisms by which maternal
physiology influences the fetal circadian pacemaker, and 3. To identify
aspects of SCN development that might be subject to modification and
therefore lead to long-term disruption of circadian regulation. The
Specific Aims are to test hypotheses in four critical areas: l. The role
of the pineal gland hormone melatonin in the development of the mammalian
circadian pacemaker, 2. The role of a specific fetal neurotransmitter
system (dopamine) in the development of the circadian pacemaker; 3. The
prenatal development of the SCN at the time pacemaker function begins, and
4. The postnatal development of the SCN at the time neural connections
from the eyes are formed. The functional development of the pacemaker will
be assessed by measuring behavioral rhythms of young hamsters and of
hamsters that have received grafts of the fetal SCN. The development of
the SCN will be examined with anatomical methods that include
immunohistochemistry, in situ hybridization, and receptor binding assays.
A unique strain of hamsters with a mutation that affects circadian rhythms
will also be used. Knowledge of SCN development is essential to understand
the normal as well as abnormal regulation of circadian rhythms. In
addition, maternal influence on the development of fetal circadian rhythms
via a dopaminergic system indicates that drugs of abuse (e.g., cocaine)
can affect the development of circadian rhythms.

## Key facts

- **NIH application ID:** 2197713
- **Project number:** 2R01HD018686-07A2
- **Recipient organization:** NORTHEASTERN UNIVERSITY
- **SAM.gov UEI:** HLTMVS2JZBS6
- **Principal Investigator:** Frederick C. Davis
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1994
- **Award amount:** $170,199
- **Award type:** 2
- **Project period:** 1984-04-01 → 1998-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/2197713

## Citation

> US National Institutes of Health, RePORTER application 2197713, DEVELOPMENT OF CIRCADIAN RHYTHMS (2R01HD018686-07A2). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/2197713. Licensed CC0.

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