-
[show abstract]
[hide abstract]
ABSTRACT: Restricted, repetitive behaviours (e.g., stereotypies, compulsions, rituals) in neurodevelopmental disorders have been linked to alterations in cortico-basal ganglia circuitry. Cognitive processes mediated by this circuitry (e.g., procedural learning, executive function) are likely to be impaired in individuals exhibiting high rates of repetitive behaviour. To test this hypothesis, we assessed both procedural learning and cognitive flexibility (reversal learning) using a T-maze task in deer mice (Peromyscus maniculatus) exhibiting various rates of repetitive behaviour (vertical jumping and backward somersaulting). These mice exhibited high rates of stereotypy when reared in standard rodent cages, and such behaviour was significantly attenuated by housing them in larger more complex environments. Mice reared in complex environments exhibited significantly better procedural and reversal learning than standard caged mice. Thus, early experience associated with the prevention and attenuation of stereotypy was associated with better striatally mediated learning and cognitive flexibility. Stereotypy score was significantly correlated with the number of errors made in reversal learning, and interacted with housing condition to affect overall cognitive performance. Our findings support the applicability of the deer mouse model of spontaneous stereotypy to a wider range of restricted, repetitive behaviour (e.g., insistence on sameness) typical of neurodevelopmental disorders.
Behavioural Brain Research 07/2008; 189(2):250-6. · 3.42 Impact Factor
-
Eric A Storch,
Lisa J Merlo,
Michael Bengtson,
Tanya K Murphy,
Mark H Lewis, Mark C Yang,
Marni L Jacob,
Michael Larson,
Adam Hirsh,
Melanie Fernandez,
Gary R Geffken,
Wayne K Goodman
[show abstract]
[hide abstract]
ABSTRACT: Obsessive-compulsive disorder is a common, chronic, and oftentimes disabling disorder. The only established first-line treatments for obsessive-compulsive disorder are exposure and response prevention therapy and the serotonin reuptake inhibitors. Many patients do not experience complete symptom resolution with either modality and require augmentation approaches. Recent animal and clinical data suggest that D-cycloserine, a partial agonist that acts at the strychnine-insensitive glycine-recognition site of the N-methyl-D-aspartate receptor complex, may enhance extinction learning that occurs in exposure-based psychotherapies. Given this, this study examined if D-cycloserine (250 mg) enhances the overall efficacy and rate of change of exposure and response prevention therapy for adult obsessive-compulsive disorder. Participants were 24 adults meeting Diagnostic and Statistical Manual of Mental Disorders-IV criteria for obsessive-compulsive disorder. The study design was a randomized, double-blinded, placebo-controlled augmentation trial examining exposure and response prevention therapy+D-cycloserine versus exposure and response prevention therapy+placebo. All patients received 12 weekly sessions of exposure and response prevention treatment. The first session involved building a ritual hierarchy and providing psychoeducation about obsessive-compulsive disorder. The second session involved a practice exposure. Sessions 3-12 involved exposure and response prevention exercises. D-cycloserine or placebo (250 mg) was taken 4 h before every session. No significant group differences were found across outcome variables. The rate of improvement did not differ between groups. The present results fail to support the use of D-cycloserine with exposure and response prevention therapy for adult obsessive-compulsive disorder. As this study is the first to explore this question and a number of methodological issues must be considered when interpreting the findings, the conclusions that may be drawn from our results are limited.
International Clinical Psychopharmacology 08/2007; 22(4):230-7. · 2.92 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The present study evaluated whether environmental enrichment-related effects on the development of stereotyped behavior in deer mice were associated with alterations in neuronal metabolic activity. Deer mice were reared under either enriched or standard housing conditions for 60 days following weaning. All mice were then placed in automated photocell detectors and classified as either stereotypic or non-stereotypic. Neuronal metabolic activity was then assessed using cytochrome oxidase (CO) histochemistry. The results demonstrated that environmental enrichment significantly increased neuronal metabolic activity in the motor cortex. Furthermore, non-stereotypic mice exhibited significantly more CO activity than stereotypic mice in the cortex, striatum, nucleus accumbens, thalamus, hippocampus and amygdala. This latter effect was due to the enriched mice as evidenced by a significant interaction between housing condition and behavioral status in the cortex, striatum, nucleus accumbens, thalamus and hippocampus. Thus, the observed increase in CO activity reflected increased neuronal metabolic activity in non-stereotypic enriched mice relative to stereotypic enriched mice. These results suggest that, in a developmental model of spontaneous stereotypy, the enrichment-related prevention of stereotyped behavior is associated with increased CO activity.
Brain Research 06/2002; 938(1-2):15-21. · 2.73 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To effectively evaluate treatments for hypertension, researchers and clinicians must be able to measure blood pressure (BP) in a valid and reliable way. The purpose of this study is to compare measurements made in the clinic using beat-to-beat radial BP tonometry, measurements made during 24 hours using an ambulatory BP monitor, and measurements made in the clinic using an automated oscillometric BP monitor. Fifty-seven adults with primary hypertension participated in this study, which used a repeated measures descriptive design. Clinic and ABPM daytime averages were compatible for both SBP and DBP. In contrast, clinic SBP was 7.56 mmHg higher than the beat-to-beat SBP; clinic DBP was 9.83 mmHg higher than the beat-to-beat DBP. These data suggest that automated clinic measurements may be used in place of daytime ambulatory BP measurements. We also estimate sample sizes for future studies based on characteristics of clinic BP.
Journal of Nursing Measurement 11(1):73-86.
