Sex-Specific Brain Deficits in Auditory Processing in an Animal Model of Cocaine-Related Schizophrenic Disorders

Cocaine is a psychostimulant in the pharmacological class of drugs called Local Anesthetics. Interestingly, cocaine is the only drug in this class that has a chemical formula comprised of a tropane ring and is, moreover, addictive. The correlation between tropane and addiction is well-studied. Anoth...

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Main Authors: Patricia A. Broderick, Taylor Rosenbaum
Format: Article
Language:English
Published: MDPI AG 2013-04-01
Series:Brain Sciences
Subjects:
Online Access:http://www.mdpi.com/2076-3425/3/2/504
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spelling doaj-dfea5f373b1d4a6691e91d6cad44ae632020-11-25T00:29:25ZengMDPI AGBrain Sciences2076-34252013-04-013250452010.3390/brainsci3020504Sex-Specific Brain Deficits in Auditory Processing in an Animal Model of Cocaine-Related Schizophrenic DisordersPatricia A. BroderickTaylor RosenbaumCocaine is a psychostimulant in the pharmacological class of drugs called Local Anesthetics. Interestingly, cocaine is the only drug in this class that has a chemical formula comprised of a tropane ring and is, moreover, addictive. The correlation between tropane and addiction is well-studied. Another well-studied correlation is that between psychosis induced by cocaine and that psychosis endogenously present in the schizophrenic patient. Indeed, both of these psychoses exhibit much the same behavioral as well as neurochemical properties across species. Therefore, in order to study the link between schizophrenia and cocaine addiction, we used a behavioral paradigm called Acoustic Startle. We used this acoustic startle paradigm in female versus male Sprague-Dawley animals to discriminate possible sex differences in responses to startle. The startle method operates through auditory pathways in brain via a network of sensorimotor gating processes within auditory cortex, cochlear nuclei, inferior and superior colliculi, pontine reticular nuclei, in addition to mesocorticolimbic brain reward and nigrostriatal motor circuitries. This paper is the first to report sex differences to acoustic stimuli in Sprague-Dawley animals (Rattus norvegicus) although such gender responses to acoustic startle have been reported in humans (Swerdlow et al. 1997 [1]). The startle method monitors pre-pulse inhibition (PPI) as a measure of the loss of sensorimotor gating in the brain's neuronal auditory network; auditory deficiencies can lead to sensory overload and subsequently cognitive dysfunction. Cocaine addicts and schizophrenic patients as well as cocaine treated animals are reported to exhibit symptoms of defective PPI (Geyer et al., 2001 [2]). Key findings are: (a) Cocaine significantly reduced PPI in both sexes. (b) Females were significantly more sensitive than males; reduced PPI was greater in females than in males. (c) Physiological saline had no effect on startle in either sex. Thus, the data elucidate gender-specificity to the startle response in animals. Finally, preliminary studies show the effect of cocaine on acoustic startle in tandem with effects on estrous cycle. The data further suggest that hormones may play a role in these sex differences to acoustic startle reported herein.http://www.mdpi.com/2076-3425/3/2/504cocaineschizophreniaaddictionsexual dimorphismmesocorticolimbicnigrostriatalneuronal circuitsponssensory-motor gatingpsychostimulantsdorsocochlear nucleusinferiorsuperior colliculiacoustic nerve
collection DOAJ
language English
format Article
sources DOAJ
author Patricia A. Broderick
Taylor Rosenbaum
spellingShingle Patricia A. Broderick
Taylor Rosenbaum
Sex-Specific Brain Deficits in Auditory Processing in an Animal Model of Cocaine-Related Schizophrenic Disorders
Brain Sciences
cocaine
schizophrenia
addiction
sexual dimorphism
mesocorticolimbic
nigrostriatal
neuronal circuits
pons
sensory-motor gating
psychostimulants
dorsocochlear nucleus
inferior
superior colliculi
acoustic nerve
author_facet Patricia A. Broderick
Taylor Rosenbaum
author_sort Patricia A. Broderick
title Sex-Specific Brain Deficits in Auditory Processing in an Animal Model of Cocaine-Related Schizophrenic Disorders
title_short Sex-Specific Brain Deficits in Auditory Processing in an Animal Model of Cocaine-Related Schizophrenic Disorders
title_full Sex-Specific Brain Deficits in Auditory Processing in an Animal Model of Cocaine-Related Schizophrenic Disorders
title_fullStr Sex-Specific Brain Deficits in Auditory Processing in an Animal Model of Cocaine-Related Schizophrenic Disorders
title_full_unstemmed Sex-Specific Brain Deficits in Auditory Processing in an Animal Model of Cocaine-Related Schizophrenic Disorders
title_sort sex-specific brain deficits in auditory processing in an animal model of cocaine-related schizophrenic disorders
publisher MDPI AG
series Brain Sciences
issn 2076-3425
publishDate 2013-04-01
description Cocaine is a psychostimulant in the pharmacological class of drugs called Local Anesthetics. Interestingly, cocaine is the only drug in this class that has a chemical formula comprised of a tropane ring and is, moreover, addictive. The correlation between tropane and addiction is well-studied. Another well-studied correlation is that between psychosis induced by cocaine and that psychosis endogenously present in the schizophrenic patient. Indeed, both of these psychoses exhibit much the same behavioral as well as neurochemical properties across species. Therefore, in order to study the link between schizophrenia and cocaine addiction, we used a behavioral paradigm called Acoustic Startle. We used this acoustic startle paradigm in female versus male Sprague-Dawley animals to discriminate possible sex differences in responses to startle. The startle method operates through auditory pathways in brain via a network of sensorimotor gating processes within auditory cortex, cochlear nuclei, inferior and superior colliculi, pontine reticular nuclei, in addition to mesocorticolimbic brain reward and nigrostriatal motor circuitries. This paper is the first to report sex differences to acoustic stimuli in Sprague-Dawley animals (Rattus norvegicus) although such gender responses to acoustic startle have been reported in humans (Swerdlow et al. 1997 [1]). The startle method monitors pre-pulse inhibition (PPI) as a measure of the loss of sensorimotor gating in the brain's neuronal auditory network; auditory deficiencies can lead to sensory overload and subsequently cognitive dysfunction. Cocaine addicts and schizophrenic patients as well as cocaine treated animals are reported to exhibit symptoms of defective PPI (Geyer et al., 2001 [2]). Key findings are: (a) Cocaine significantly reduced PPI in both sexes. (b) Females were significantly more sensitive than males; reduced PPI was greater in females than in males. (c) Physiological saline had no effect on startle in either sex. Thus, the data elucidate gender-specificity to the startle response in animals. Finally, preliminary studies show the effect of cocaine on acoustic startle in tandem with effects on estrous cycle. The data further suggest that hormones may play a role in these sex differences to acoustic startle reported herein.
topic cocaine
schizophrenia
addiction
sexual dimorphism
mesocorticolimbic
nigrostriatal
neuronal circuits
pons
sensory-motor gating
psychostimulants
dorsocochlear nucleus
inferior
superior colliculi
acoustic nerve
url http://www.mdpi.com/2076-3425/3/2/504
work_keys_str_mv AT patriciaabroderick sexspecificbraindeficitsinauditoryprocessinginananimalmodelofcocainerelatedschizophrenicdisorders
AT taylorrosenbaum sexspecificbraindeficitsinauditoryprocessinginananimalmodelofcocainerelatedschizophrenicdisorders
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