Male hamsters will be used in a series of studies designed to provide information about neural control of circadian rhythm and photoperiodic time measurement. (1) Knife cuts or chemical lesions will destroy selected afferent systems of the suprachiasmatic nuclei; (2) Knife cuts will be made around the suprachiasmatic nuclei to sever their efferent connections with adjacent hypothalamus; (3) The two suprachiasmatic nuclei and the associated optic chiasm will be separated along the midline. Locomotion and body temperature rhythms will be continuously monitored and analyzed for the extent of disruption following lesions. Similarly designed experiments will test for the presence or absence of short photoperiod induced gonadal regression following the lesions. Nissl and immunohistochemical stains as well as amino acid autoradiographic techniques will be used to assess the effectiveness of the cuts and lesions. The studies will elucidate neuroanatomical control of two circadian rhythms and permit comparison with neuroanatomical control of photoperiodism.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS022168-02
Application #
3404252
Study Section
Biopsychology Study Section (BPO)
Project Start
1985-04-01
Project End
1988-03-31
Budget Start
1986-04-01
Budget End
1987-03-31
Support Year
2
Fiscal Year
1986
Total Cost
Indirect Cost
Name
State University New York Stony Brook
Department
Type
Schools of Medicine
DUNS #
804878247
City
Stony Brook
State
NY
Country
United States
Zip Code
11794
Morin, Lawrence P (2013) Neuroanatomy of the extended circadian rhythm system. Exp Neurol 243:4-20
Morin, Lawrence P; Hefton, Sara; Studholme, Keith M (2011) Neurons identified by NeuN/Fox-3 immunoreactivity have a novel distribution in the hamster and mouse suprachiasmatic nucleus. Brain Res 1421:44-51
Morin, Lawrence P; Lituma, Pablo J; Studholme, Keith M (2010) Two components of nocturnal locomotor suppression by light. J Biol Rhythms 25:197-207
Morin, L P; Studholme, K M (2009) Millisecond light pulses make mice stop running, then display prolonged sleep-like behavior in the absence of light. J Biol Rhythms 24:497-508
Goz, Didem; Studholme, Keith; Lappi, Douglas A et al. (2008) Targeted destruction of photosensitive retinal ganglion cells with a saporin conjugate alters the effects of light on mouse circadian rhythms. PLoS One 3:e3153
Vidal, Luis; Morin, Lawrence P (2007) Absence of normal photic integration in the circadian visual system: response to millisecond light flashes. J Neurosci 27:3375-82
Morin, Lawrence P (2007) SCN organization reconsidered. J Biol Rhythms 22:3-13
Morin, L P; Allen, C N (2006) The circadian visual system, 2005. Brain Res Rev 51:1-60
Muscat, L; Morin, L P (2006) Intergeniculate leaflet: contributions to photic and non-photic responsiveness of the hamster circadian system. Neuroscience 140:305-20
Morin, L P; Shivers, K-Y; Blanchard, J H et al. (2006) Complex organization of mouse and rat suprachiasmatic nucleus. Neuroscience 137:1285-97

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