Publication Date


Document Type


Committee Members

David Ladle (Advisor), Mark Rich (Committee Member), Patrick Sonner (Committee Member)

Degree Name

Master of Science (MS)


The monosynaptic stretch reflex circuit is one of the simplest circuits of the central nervous system. We studied the connection between Ia proprioceptive afferents and motor neurons that comprise the circuit, by stimulating the dorsal root and recording from the ventral root of the fourth lumbar spinal nerve. In our study, we analyzed the status of neurotransmission in the stretch reflex circuit in postnatal PV-cre; munc18-1 lox/lox conditional mutant mice. Munc18-1 is responsible for synaptic vesicular release in neurons. In the PV-cre; Munc18-1 lox/lox mutants we use, Munc18-1 is only knocked out in proprioceptive afferents and A-beta somatosensory afferents, both of which express parvalbumin (PV). Our results showed that on the first postnatal day (P1), responses evoked from the ventral root are significantly reduced in mutants compared to wild type mice. Similar results were also observed at P6. Our results lead us to conclude that PV-cre; Munc18-1 lox/lox mutant mice lack synaptic vesicular release in proprioceptive afferents after birth as evidenced by a dramatically reduced stretch reflex circuit response analyzed with the electrophysiology experiments in our study.

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Department or Program

Department of Neuroscience, Cell Biology and Physiology

Year Degree Awarded


Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.

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