Bilateral Lesion of Nucleus Reticularis Pontis Caudalis
Objective: To delineate a primary acoustic startle circuit by performing bilateral lesions of ventral regions of the nucleus reticularis pontis caudalis and evaluating the effect on acoustic startle reflex in rats
Gather these items before starting the experiment. Check off items as you prepare.
Equipment4
Materials1
Not specified • Not specified • Not specified • Not specified
As an Amazon Associate, we earn from qualifying purchases. Product links help support this free resource.
Protocol Steps
Baseline acoustic startle measurement
Measure baseline latency of acoustic startle reflex from tone onset to electromyographic response in hindleg
Note: Baseline latency is approximately 8 msec
View evidence from paper
“The latency of the acoustic startle reflex in the rat is 8 msec, measured from tone onset to the beginning of the electromyographic response in the hindleg”
Create bilateral lesions of ventral nucleus reticularis pontis caudalis
Perform bilateral lesions of ventral regions of the nucleus reticularis pontis caudalis, which contain cell bodies giving rise to the reticulospinal tract
Note: Lesions must be bilateral and target ventral regions specifically
View evidence from paper
“Bilateral lesions of ventral regions of the nucleus reticularis pontis caudalis, which contain cell bodies that give rise to the reticulospinal tract, abolish acoustic startle”
Post-lesion acoustic startle assessment
Measure acoustic startle reflex following bilateral lesions to determine if startle response is abolished
Note: Expected outcome is abolishment of acoustic startle
View evidence from paper
“Bilateral lesions of ventral regions of the nucleus reticularis pontis caudalis, which contain cell bodies that give rise to the reticulospinal tract, abolish acoustic startle”
Electrical stimulation of lesioned region
Apply single pulse electrical stimulation to the lesioned nucleus reticularis pontis caudalis region to determine if startle-like responses can be elicited
Note: Stimulation of ventral regions elicits startle-like responses with latency of approximately 5 msec
View evidence from paper
“Electrical stimulation of these points elicits startle-like responses with a latency of about 5 msec”
Neural tracing with horseradish peroxidase
Iontophorese horseradish peroxidase into the nucleus reticularis pontis caudalis region to identify neural connections and trace projections to other brain regions
Note: Reaction product is found in nuclei of the lateral lemniscus, indicating connectivity
View evidence from paper
“Reaction product from horseradish peroxidase iontophoresed into this area is found in the nuclei of the lateral lemniscus”