Behavioral correlates of vitamin D deficiency

Impaired spatial memory in adult vitamin D deficient BALB/c mice is associated with reductions in spine density, nitric oxide, and neural nitric oxide synthase in the hippocampus

Vitamin D deficiency is prevalent in adults and is associated with cognitive impairment. However, the mechanism by which adult vitamin D (AVD) deficiency affects cognitive function remains unclear. We examined spatial memory impairment in AVD-deficient BALB/c mice and its underlying mechanism by measuring spine density, long term potentiation (LTP), nitric oxide (NO), neuronal nitric oxide synthase (nNOS), and endothelial NOS (eNOS) in the hippocampus. Adult male BALB/c mice were fed a control or vitamin D deficient diet for 20 weeks. Spatial memory performance was measured using an active place avoidance (APA) task, where AVD-deficient mice had reduced latency entering the shock zone compared to controls. We characterised hippocampal spine morphology in the CA1 and dentate gyrus (DG) and made electrophysiological recordings in the hippocampus of behaviourally naïve mice to measure LTP. We next measured NO, as well as glutathione, lipid peroxidation and oxidation of protein products and quantified hippocampal immunoreactivity for nNOS and eNOS. Spine morphology analysis revealed a significant reduction in the number of mushroom spines in the CA1 dendrites but not in the DG. There was no effect of diet on LTP. However, hippocampal NO levels were depleted whereas other oxidation markers were unaltered by AVD deficiency. We also showed a reduced nNOS, but not eNOS, immunoreactivity. Finally, vitamin D supplementation for 10 weeks to AVD-deficient mice restored nNOS immunoreactivity to that seen in in control mice. Our results suggest that lower levels of NO and reduced nNOS immunostaining contribute to hippocampal-dependent spatial learning deficits in AVD-deficient mice.

The role of vitamin D in bipolar disorder: Epidemiology and influence on disease activity

BACKGROUND

Although many studies found an association between psychiatric disorders, especially major depressive disorder, and vitamin D deficiency, little is still known about the association between vitamin D and bipolar disorder (BD). Therefore, the present review aims at providing an overview of the available literature exploring the role of vitamin D in BD patients in different phases of the disease.

METHODS

From a bibliographic research in PubMed until April 2020, we collected ten original studies that fulfilled our inclusion criteria.

RESULTS

No significant differences in vitamin D levels between BD patients and other psychiatric disorders were found by most of the studies. In the majority of the studies, the average values of vitamin D in BD population were sub-threshold for vitamin D deficiency. Moreover, although an association between vitamin D levels and clinical symptomatology was observed in BD patients, it cannot be considered a specific marker of this disorder but a common characteristic shared with other psychiatric disorders, including schizophrenia and major depressive disorder. Finally, vitamin D supplementation was associated with a reduction in both depressive and manic symptoms.

LIMITATIONS

Few studies with small and heterogeneous populations. Methodological heterogeneity in terms of vitamin D measurement and threshold.

CONCLUSIONS

The results showed that vitamin D status does not differ between BD and other psychiatric conditions. However, given the correlation between vitamin D levels and depressive or manic symptoms, we could hypothesize that an adequate vitamin D status could positively affect the mood balance thanks to its immunomodulatory activity.

Adult vitamin D deficiency disrupts hippocampal-dependent learning and structural brain connectivity in BALB/c mice

Converging evidence from human and animal studies support an association between vitamin D deficiency and cognitive impairment. Previous studies have shown that hippocampal volume is reduced in adults with vitamin D deficiency as well as in a range of disorders, such as schizophrenia. The aim of the current study was to examine the effect of adult vitamin D (AVD) deficiency on hippocampal-dependent spatial learning, and hippocampal volume and connectivity in healthy adult mice. Ten-week-old male BALB/c mice were fed a control (vitamin D 1500 IU/kg) or vitamin D-depleted (vitamin D 0 IU/kg) diet for a minimum of 10 weeks. The mice were then tested for hippocampal-dependent spatial learning using active place avoidance (APA) and on tests of muscle and motor coordination (rotarod and grip strength). The mice were perfused and brains collected to acquire ex vivo structural and diffusion-weighted images using a 16.4 T MRI scanner. We also performed immunohistochemistry to quantify perineuronal nets (PNNs) and parvalbumin (PV) interneurons in various brain regions. AVD-deficient mice had a lower latency to enter the shock zone on APA, compared to control mice, suggesting impaired hippocampal-dependent spatial learning. There were no differences in rotarod or grip strength, indicating that AVD deficiency did not have an impact on muscle or motor coordination. AVD deficiency did not have an impact on hippocampal volume. However, AVD-deficient mice displayed a disrupted network centred on the right hippocampus with abnormal connectomes among 29 nodes. We found a reduction in PNN positive cells, but no change in PV, centred on the hippocampus. Our results provide compelling evidence to show that AVD deficiency in otherwise healthy adult mice may play a key role in hippocampal-dependent learning and memory formation. We suggest that the spatial learning deficits could be due to the disruption of right hippocampal structural connectivity.

Vitamin D protects dopaminergic neurons against neuroinflammation and oxidative stress in hemiparkinsonian rats

BACKGROUND

The deficiency in 1α, 25-dihydroxyvitamin D3 (VD3) seems to increase the risk for neurodegenerative pathologies, including Parkinson's disease (PD). The majority of its actions are mediated by the transcription factor, VD3 receptor (VD3R).

METHODS

The neuroprotective effects of VD3 were investigated on a PD model. Male Wistar rats were divided into the following groups: sham-operated (SO), 6-OHDA-lesioned (non-treated), and 6-OHDA-lesioned and treated with VD3 (7 days before the lesion, pre-treatment or for 14 days after the 6-OHDA striatal lesion, post-treatment). Afterwards, the animals were subjected to behavioral tests and euthanized for striatal neurochemical and immunohistochemical assays. The data were analyzed by ANOVA and the Tukey test and considered significant for p < 0.05.

RESULTS

We showed that pre- or post-treatments with VD3 reversed behavioral changes and improved the decreased DA contents of the 6-OHDA group. In addition, VD3 reduced the oxidative stress, increased (TH and DAT), and reduced (TNF-alpha) immunostainings in the lesioned striata. While significant decreases in VD3R immunoreactivity were observed after the 6-OHDA lesion, these changes were blocked after VD3 pre- or post-treatments. We showed that VD3 offers neuroprotection, decreasing behavioral changes, DA depletion, and oxidative stress. In addition, it reverses partially or completely TH, DAT, TNF-alpha, and VD3R decreases of immunoreactivities in the non-treated 6-OHDA group.

CONCLUSIONS

Taken together, VD3 effects could result from its anti-inflammatory and antioxidant actions and from its actions on VD3R. These findings should stimulate translational research towards the VD3 potential for prevention or treatment of neurodegenerative diseases, as PD.

Developmental vitamin D deficiency and schizophrenia: the role of animal models

Schizophrenia is a debilitating neuropsychiatric disorder that affects 1% of the US population. Based on twin and genome-wide association studies, it is clear that both genetics and environmental factors increase the risk for developing schizophrenia. Moreover, there is evidence that conditions in utero, either alone or in concert with genetic factors, may alter neurodevelopment and lead to an increased risk for schizophrenia. There has been progress in identifying genetic loci and environmental exposures that increase risk, but there are still considerable gaps in our knowledge. Furthermore, very little is known about the specific neurodevelopmental mechanisms upon which genetics and the environment act to increase disposition to developing schizophrenia in adulthood. Vitamin D deficiency during the perinatal period has been hypothesized to increase risk for schizophrenia in humans. The developmental vitamin D (DVD) deficiency hypothesis of schizophrenia arises from the observation that disease risk is increased in individuals who are born in winter or spring, live further from the equator or live in urban vs. rural settings. These environments result in less exposure to sunlight, thereby reducing the initial steps in the production of vitamin D. Rodent models have been developed to characterize the behavioral and developmental effects of DVD deficiency. This review focuses on these animal models and discusses the current knowledge of the role of DVD deficiency in altering behavior and neurobiology relevant to schizophrenia.

Vitamin D and/or calcium deficient diets may differentially affect muscle fiber neuromuscular junction innervation

INTRODUCTION

There is evidence that supports a role for Vitamin D (Vit. D) in muscle. The exact mechanism by which Vit. D deficiency impairs muscle strength and function is not clear.

METHODS

Three-week-old mice were fed diets with varied combinations of Vit. D and Ca²⁺ deficiency. Behavioral testing, genomic and protein analysis, and muscle histology were performed with a focus on neuromuscular junction (NMJ) -related genes.

RESULTS

Vit. D and Ca²⁺ deficient mice performed more poorly on given behavioral tasks than animals with Vit. D deficiency alone. Genomic and protein analysis of the soleus and tibialis anterior muscles revealed changes in several Vit. D metabolic, NMJ-related, and protein chaperoning and refolding genes.

CONCLUSIONS

These data suggest that detrimental effects of a Vit. D deficient or a Vit. D and Ca²⁺ deficient diet may be a result of differential alterations in the structure and function of the NMJ and a lack of a sustained stress response in muscles. Muscle Nerve 54: 1120-1132, 2016.

Vitamin D as a neurosteroid affecting the developing and adult brain

Vitamin D deficiency is prevalent throughout the world, and growing evidence supports a requirement for optimal vitamin D levels for the healthy developing and adult brain. Vitamin D has important roles in proliferation and differentiation, calcium signaling within the brain, and neurotrophic and neuroprotective actions; it may also alter neurotransmission and synaptic plasticity. Recent experimental studies highlight the impact that vitamin D deficiency has on brain function in health and disease. In addition, results from recent animal studies suggest that vitamin D deficiency during adulthood may exacerbate underlying brain disorders and/or worsen recovery from brain stressors. An increasing number of epidemiological studies indicate that vitamin D deficiency is associated with a wide range of neuropsychiatric disorders and neurodegenerative diseases. Vitamin D supplementation is readily available and affordable, and this review highlights the need for further research.

The impact of adult vitamin D deficiency on behaviour and brain function in male Sprague-Dawley rats

Background

Vitamin D deficiency is common in the adult population, and this has been linked to depression and cognitive outcomes in clinical populations. The aim of this study was to investigate the effects of adult vitamin D (AVD) deficiency on behavioural tasks of relevance to neuropsychiatric disorders in male Sprague-Dawley rats.

Methods

Ten-week old male Sprague-Dawley rats were fed a control or vitamin D deficient diet for 6 weeks prior to, and during behavioural testing. We first examined a range of behavioural domains including locomotion, exploration, anxiety, social behaviour, learned helplessness, sensorimotor gating, and nociception. We then assessed locomotor response to the psychomimetic drugs, amphetamine and MK-801. Attention and vigilance were assessed using the 5 choice serial reaction time task (5C-SRT) and the 5 choice continuous performance task (5C-CPT) and, in a separate cohort, working memory was assessed using the delay match to sample (DMTS) task. We also examined excitatory and inhibitory neurotransmitters in prefrontal cortex and striatum.

Results

AVD-deficient rats were deficient in vitamin D₃ (<10 nM) and had normal calcium and phosphate levels after 8–10 weeks on the diet. Overall, AVD deficiency was not associated with an altered phenotype across the range of behavioural domains tested. On the 5C-SRT AVD-deficient rats made more premature responses and more head entries during longer inter-trial intervals (ITI) than control rats. On the 5C-CPT AVD-deficient rats took longer to make false alarm (FA) responses than control rats. AVD-deficient rats had increases in baseline GABA levels and the ratio of DOPAC/HVA within the striatum.

Conclusions

AVD-deficient rats exhibited no major impairments in any of the behavioural domains tested. Impairments in premature responses in AVD-deficient rats may indicate that these animals have specific alterations in striatal systems governing compulsive or reward-seeking behaviour.

Vitamin D, effects on brain development, adult brain function and the links between low levels of vitamin D and neuropsychiatric disease

Increasingly vitamin D deficiency is being associated with a number of psychiatric conditions. In particular for disorders with a developmental basis, such as autistic spectrum disorder and schizophrenia the neurobiological plausibility of this association is strengthened by the preclinical data indicating vitamin D deficiency in early life affects neuronal differentiation, axonal connectivity, dopamine ontogeny and brain structure and function. More recently epidemiological associations have been made between low vitamin D and psychiatric disorders not typically associated with abnormalities in brain development such as depression and Alzheimer's disease. Once again the preclinical findings revealing that vitamin D can regulate catecholamine levels and protect against specific Alzheimer-like pathology increase the plausibility of this link. In this review we have attempted to integrate this clinical epidemiology with potential vitamin D-mediated basic mechanisms. Throughout the review we have highlighted areas where we think future research should focus.

ABNORMAL BEHAVIORAL ORGANIZATION OF GROOMING IN MICE LACKING THE VITAMIN D RECEPTOR GENE

Vitamin D is a steroid hormone with several important functions in the nervous system. Numerous human and animal data link alterations in the vitamin D system to various behavioral disorders. Grooming is an important element of rodent behavior with a general pattern of cephalocaudal progression (paw licking - nose/face wash - body wash - tail/genitals wash). Here we studied whether genetic ablation of vitamin D nuclear receptors (VDR) in mice may be associated with altered behavioral sequencing of grooming. Overall, VDR null mutant mice showed abnormal grooming, including a higher percentage of "incorrect" transitions and longer duration of "incorrect" grooming (contrary to the cephalocaudal progression); a higher percentage of interrupted grooming bouts; and the atypical regional distribution of grooming (more leg grooming, less body and tail/genitals grooming), compared to their wild-type controls. Grooming of heterozygous mice was similar to the wild-type group, indicating that abnormal grooming patterning is inherited as a recessive. In contrast, behavioral sequencing of another complex behavior (mating with a female) was unaltered in all three genotypes, suggesting grooming-specific abnormal sequencing in these mutant mice. Our results suggest that a neurosteroid vitamin D and VDR may play an important role in controlling sequencing of grooming in mice, and further confirm the important role of the vitamin D system and VDR in the regulation of behavior.

Premature aging in vitamin D receptor mutant mice

Hypervitaminosis vitamin D(3) has been recently implicated in premature aging through the regulation of 1alpha hydroxylase expression by klotho and fibroblast growth factor-23 (Fgf-23). Here we examined whether the lack of hormonal function of vitamin D(3) in mice is linked to aging phenomena. For this, we used vitamin D(3) receptor (VDR) "Tokyo" knockout (KO) mice (fed with a special rescue diet) and analyzed their growth, skin and cerebellar morphology, as well as overall motor performance. We also studied the expression of aging-related genes, such as Fgf-23, nuclear factor kappaB (NF-kappaB), p53, insulin like growth factor 1 (IGF1) and IGF1 receptor (IGF1R), in liver, as well as klotho in liver, kidney and prostate tissues. Overall, VDR KO mice showed several aging related phenotypes, including poorer survival, early alopecia, thickened skin, enlarged sebaceous glands and development of epidermal cysts. There was no difference either in the structure of cerebellum or in the number of Purkinje cells. Unlike the wildtype controls, VDR KO mice lose their ability to swim after 6 months of age. Expression of all the genes was lower in old VDR KO mice, but only NF-kappaB, Fgf-23, p53 and IGF1R were significantly lower. Since the phenotype of aged VDR knockout mice is similar to mouse models with hypervitaminosis D(3), our study suggests that VDR genetic ablation promotes premature aging in mice, and that vitamin D(3) homeostasis regulates physiological aging.

Is there convincing biological or behavioral evidence linking vitamin D deficiency to brain dysfunction?

Vitamin D insufficiency is common in the United States; the elderly and African-Americans are at particularly high risk of deficiency. This review, written for a broad scientific readership, presents a critical overview of scientific evidence relevant to a possible causal relationship between vitamin D deficiency and adverse cognitive or behavioral effects. Topics discussed are 1) biological functions of vitamin D relevant to cognition and behavior; 2) studies in humans and rodents that directly examine effects of vitamin D inadequacy on cognition or behavior; and 3) immunomodulatory activity of vitamin D relative to the proinflammatory cytokine theory of cognitive/behavioral dysfunction. We conclude there is ample biological evidence to suggest an important role for vitamin D in brain development and function. However, direct effects of vitamin D inadequacy on cognition/behavior in human or rodent systems appear to be subtle, and in our opinion, the current experimental evidence base does not yet fully satisfy causal criteria. Possible explanations for the apparent inconsistency between results of biological and cognitive/behavioral experiments, as well as suggested areas for further research are discussed. Despite residual uncertainty, recommendations for vitamin D supplementation of at-risk groups, including nursing infants, the elderly, and African-Americans appear warranted to ensure adequacy.

No association between serum 25-hydroxyvitamin D3 level and performance on psychometric tests in NHANES III

BACKGROUND

Animal studies and in vitro experiments indicate that vitamin D is involved in a diverse range of neurobiological functions. We had the opportunity to examine the relationship between serum 25-hydroxyvitamin D(3) [25(OH)D] levels and performance on various cognitive tasks, based on a large, representative community sample.

METHODS

Three age groups were available from the population-based NHANES III survey: adolescent group (n = 1,676, age range 12-17 years), adult group (n = 4,747, 20-60 years), elderly group (n = 4,809, 60-90 years). The associations between eight psychometric measures and serum 25(OH)D were assessed.

RESULTS

In the adolescent and adult groups, none of the psychometric measures were associated with 25(OH)D levels. In the elderly group there was a significant difference between 25(OH)D quintiles performance on a learning and memory task; however, those with the highest quintile of 25(OH)D were most impaired on the task, contrary to the hypotheses.

CONCLUSION

Lower 25(OH)D levels were not associated with impaired performance on various psychometric measures. While it remains to be seen if chronic exposure to low 25(OH)D levels alters brain function in the long term, this cross-sectional study suggests that 25(OH)D levels do not influence neurocognitive performance.

Neophobia, sensory and cognitive functions, and hedonic responses in vitamin D receptor mutant mice

Vitamin D is a seco-steroid hormone with multiple actions in the brain, mediated through the nuclear vitamin D receptor (VDR). We have recently shown that mutant mice lacking functional VDR demonstrate altered emotional behavior and specific motor deficits. Here we further examine phenotype of these mice, testing their novelty responses, as well as cognitive and sensory (olfactory and gustatory) functions in the novel food, two-trial Y-maze and tastant consumption tests. In addition, we study depression-like behavior in these mice, using anhedonia-based sucrose preference test. Overall, VDR mutant mice showed neophobic response in several different tests, but displayed unimpaired olfactory and gustatory functions, spatial memory and baseline hedonic responses. Collectively, these data confirm that mutation of VDR in mice leads to altering emotional/anxiety states, but does not play a major role in depression, as well as in the regulation of some sensory and cognitive processes. These results support the role of the vitamin D/VDR neuroendocrine system in the regulation of behavior, and may have clinical relevance, enabling a better focus on psychiatric and behavioral disorders associated with dysfunctions in this neuroendocrine system.

Aberrant nest building and prolactin secretion in vitamin D receptor mutant mice

1Alpha,25(OH)2D3, the hormonal form of vitamin D, is a neuroactive seco-steroid hormone with multiple functions in the brain. Most of these effects are mediated through the nuclear vitamin D receptor (VDR), widely distributed in the central nervous system. Our earlier studies showed that mutant mice lacking functional VDR have specific behavioural abnormalities, including anxiety and aberrant maternal behaviour, which may be hormonally regulated. Here we describe impaired nest building behaviour in VDR mutant mice. Since prolactin plays a key role in the regulation of nest building in both sexes, we also examine whether VDR mutant mice have altered prolactin levels. Overall, serum prolactin levels were increased in VDR mutant mice, accompanied by marked impairments in their nest building activity. In contrast, there were no differences in prolactin mRNA expression levels between wildtype control mice and VDR mutant mice. Collectively, these data suggest that partial genetic ablation of VDR affects prolactin system in mice, and that altered serum prolactin levels in VDR mutants may underlie some of their behavioural abnormalities, such as impaired nest building.

Thalamic calcification in vitamin D receptor knockout mice

Vitamin D is a steroid hormone with many important functions in the brain, mediated through the nuclear vitamin D receptor. Here, we report that aging nuclear vitamin D receptor knockout mice demonstrate a symmetric thalamic calcification with numerous Ca/P-containing laminated bodies. These results are consistent with clinical findings showing brain calcification in patients with vitamin D deficiency. Our results suggest that nuclear vitamin D receptor deficiency leads to brain mineralization in vitamin D receptor knockout mice, which may represent an experimental model of intracranial calcification.

Behavioural anomalies in mice evoked by “Tokyo” disruption of the Vitamin D receptor gene

Vitamin D is a steroid hormone with many important functions in the brain, mediated through the nuclear Vitamin D receptor (VDR). Mounting clinical data link VDR mutations to various psychiatric phenotypes. We have reported previously that mutant mice lacking functional VDR ("Tokyo" VDR mutant mice) display several behavioural anomalies, including high anxiety and aberrant grooming. Given the important role of Vitamin D and VDR in brain development and functioning, we hypothesized that several other important behavioural domains may be affected by disruption of the VDR gene in mice. Here we report that VDR mutants display unaffected depressive-like behaviour, but show abnormal social behaviours, reduced social barbering and aggressiveness, impaired nest building and aberrant maternal (pup neglect, cannibalism) behaviours. Taken together, these findings confirm the important role postulated for the VDR in the regulation of behaviour, and suggest the mice lacking functional VDR may be a useful tool to model different brain disorders.

Transient prenatal Vitamin D deficiency is associated with hyperlocomotion in adult rats

Rat experiments have shown that prenatal Vitamin D deficiency leads to altered neonatal brain morphology, cell density and neurotrophin expression. In the current study we examined the hypothesis that Vitamin D deficiency during early development alters adult behaviour even when there is an intervening period in which the animal receives normal Vitamin D in later development. Rats were conceived and born to Vitamin D deficient dams (Birth); conceived, born and weaned from Vitamin D deficient dams (Weaning); or deficient in Vitamin D from conception to 10 weeks of age (Life). Litters were standardized to three males and three females per litter. All rat offspring were rendered normocalcaemic with calcium supplemented water (2 mM) after weaning. Control animals were born to mothers fed a normal diet but subject to similar litter size and calcium supplementation. At 10 weeks all animals were tested on the holeboard test, elevated plus maze test, social interaction observation, acoustic startle response test, prepulse inhibition of the acoustic startle response and a forced swim test. Early Vitamin D deficiency (Birth group) enhanced locomotion in the holeboard test and increased activity in the elevated plus maze. Thus, transient prenatal Vitamin D deficiency induces hyperlocomotion in adulthood, without severe motor abnormalities.

Impaired motor performance in mice lacking neurosteroid vitamin D receptors

Vitamin D is a neuroactive seco-steroid and its importance to the nervous system is receiving increasing recognition. Since numerous data link vitamin D dysfunctions to various neurological and behavioural disorders, we studied whether genetic ablation of vitamin D receptors (VDR) may be associated with motor impairments in mice subjected to several behavioural tests. The data obtained in the vertical screen and swim tests show that VDR genetic ablation produces severe motor impairment (shorter screen retention and poor swimming) in mutant mice compared to wild-type and heterozygous control animals. These impairments appear to be unrelated to visual, vestibular and activity/emotionality parameters of mice, and are likely associated with disturbed calcium homeostasis. This study confirms the important role of the vitamin D system in motor functions and suggests that animal genetic models targeting the vitamin D/VDR system may be a useful tool to study vitamin D-related motor/behavioural disorders.

Increased anxiety in mice lacking vitamin D receptor gene

Vitamin D is a steroid hormone with many important functions in the brain, mediated through the vitamin D nuclear receptor. Numerous human and animal data link vitamin D dysfunctions to various behavioural disorders. To examine this problem, we studied whether genetic ablation of vitamin D receptors in mice may be associated with altered emotional behaviours. Here we show that the receptor-deficient mice demonstrate increased anxiety-like behaviours when subjected to a battery of behavioural tests. These studies suggest that vitamin D and its receptors are an important factor in the brain, whose imbalance may significantly affect emotional behaviour.

Neurological correlates of unilateral and bilateral "strokes" of the middle cerebral artery in the rat

Rats with unilateral lesions of the middle cerebral artery (MCA) were tested for the ability to detect (touch) and remove a square of adhesive tape from each forepaw, and for performance on a number of neurological tests (e.g., placing and hopping reflexes, activity). Rats with MCA damage showed deficits in both touching and removing the tape from the paw contralateral to the damage, but not ipsilateral to the damage, while performing within normal limits on the other tests. After scores of the MCA rats dropped into the control group range on the adhesive tape test, they sustained damage to the opposite MCA. This did not reinstate the original deficit, suggesting that the recovery seen after the unilateral lesion was not mediated by the opposite cortex. The second lesion, however, caused a deficit in removing the adhesive tape from the limb opposite the new stroke. Some of the rats that originally had sham operations received bilateral MCA lesions at this time. These animals showed much more severe deficits on the adhesive tape test than the rats with sequential strokes. Rats with bilateral MCA damage (simultaneous or sequential) also slipped on a long narrow plank more often than control animals. Nimodipine did not enhance recovery on any of the behavioral measures.