Sound-induced behavioural activation in the normal and haloperidol-treated rat

Diseases of the central and peripheral nervous systems affect one in five people in North America. Parkinson’s disease (PD) is the second most common neurodegenerative disease, after Alzheimer’s disease, and occurs in approximately 1% of the general North American population. PD is a progressive movement disorder that is characterized by resting tremor, rigidity, bradykinesia (slowness of movement) or akinesia (absence of spontaneous movement), as well as postural instability. Current treatment of PD is symptom-based, and no pharmacological treatment currently exists to slow the progression of bradykinesia and akinesia. In fact, pharmacological therapies produce motor side effects in advanced stages of the disease. Given the difficulty in initiating and controlling movement as PD advances, and the ineffectiveness of medical therapies after prolonged treatment, physical and music therapies can be used to supplement classical therapies. Listening to, and performing, music affects a number of neural regions, including those that mediate motor behaviour, arousal or activation, and emotion. Despite anatomical connections between the auditory and motor systems at the level of the spinal cord, brain stem, midbrain, and cortex, the neural and behavioural mechanisms for sound-induced activation remains unclear. It is known, however, that PD patients recruit external sensory stimuli to improve movement. The aim of the current research was to create an animal model of sound-induced activation and to test the effect of previous motoric experience on the potency of auditory stimuli. To investigate behavioural activation in the normal and haloperidol-treated rat, two tasks were used: 1) orienting responses were analyzed for movement components in saline and haloperidol treated rats v to find out if rats responded in the same to a variety of naturally produced and generated activating sounds, and 2) a grid climbing task allowed for the righting components of naïve and familiar cataleptic rats to be compared. Our findings revealed that familiar auditory cues could release parkinsonian rats from catalepsy. The current research supports the theory that auditory stimulation retains “special access” to motor regions otherwise impaired in PD and likely bypasses basal ganglia circuitry to normalize movement through alternative pathways.

Authors

• Clark, Callie Anne Marie
• University of Lethbridge. Faculty of Arts and Science

• Parkinson's disease -- Research
• Rats as laboratory animals
• Motor ability -- Research
• Dissertations, Academic

Identifier

hdl:10133/1293

OAI identifier oai:identifier

oai:opus.uleth.ca:10133/1293