Neuroscience
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Multiple sclerosis (MS) is a progressive condition affecting the central nervous system (CNS), and is characterized by the development of demyelinated lesions and plaques in the brain and spinal cord. Exercise is beneficial against dementia in elderly patients, so we investigated the effects of exercise on memory in relation to hippocampal demyelination and neuroplasticity in a mouse model of MS (experimental autoimmune encephalomyelitis [EAE]). Mice were randomly divided into three groups: Sham, EAE, and EAE and exercise (EAE+EX). ⋯ We found decreased memory ability in EAE mice, accompanied by impaired myelination, increased apoptosis and cell proliferation, and decreased BDNF in the hippocampus. The memory decline and changes in demyelination, apoptosis, BDNF, and cell proliferation were partially reversed in EAE+EX mice. Our findings suggest that in patients with MS, regular exercise may benefit cognitive function by rescuing some hippocampal cellular and molecular impairments.
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A better understanding of BOLD responses stems from a better characterization of the brain's ability to metabolize glucose and oxygen. Non-invasive techniques such as functional magnetic resonance spectroscopy (fMRS) have thus been developed allowing for the reproducible assessment of metabolic changes during barrel cortex (S1BF) activations in rats. The present study aimed at further exploring the role of neurotransmitters on local and temporal changes in vascular and metabolic function in S1BF. fMRS and fMRI data were acquired sequentially in α-chloralose anesthetized rats during 32-min rest and trigeminal nerve stimulation periods. ⋯ Dynamic analysis of metabolite concentrations allowed estimating changes in cerebral metabolic rates of glucose (ΔCMRGlc) and oxygen (ΔCMRO2). Findings confirmed a prevalence of oxidative metabolism during prolonged S1BF activation. Habituation led to a significant BOLD magnitude decline as a function of time while both total ΔCMRGlc and ΔCMRO2 remained constant revealing adaptation of glucose and oxygen metabolisms to support ongoing trigeminal nerve stimulation.
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Adeno-associated viruses (AAVs) have become powerful tools in neuroscience for both basic research and potential therapeutic use. They have become especially important tools for optogenetic experiments based on their ability to achieve transgene expression in postmitotic neurons with regional selectivity. With the use of appropriate promoter elements they can achieve cellular specificity as well. ⋯ Although it showed excellent specificity in cortex and striatum, where no reporter expression was observed, in the SN region many neurons expressed reporter but not TH. We show that some of the TH negativity is due to the suppression of its expression by the transgene. We conclude that rTHp(2.5) does preferentially label dopamine neurons but its specificity is not complete within the substantia nigra and caution must be used.
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Growing evidence from epidemiological studies strongly suggests maternal infection as a risk factor for psychiatric disorders including bipolar disorder, schizophrenia, and autism. Animal studies support this association and demonstrate that maternal immune activation (MIA) changes brain morphology and inflammatory cytokines in the adult offspring. ⋯ This perspective briefly highlights convincing evidence from epidemiological, preclinical and human pathological studies to support the role of MIA in major psychiatric disorders. A better understanding of the link between MIA and brain development in psychiatric disorders will lead to the development of novel immunomodulatory interventions for individuals at risk for psychiatric disorders.
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Painful events early in life have been shown to increase the incidence of interstitial cystitis/painful bladder syndrome in adulthood. However, the intrinsic mechanism is not well studied. We previously reported that neonatal bladder inflammation causes chronic visceral hypersensitivity along with molecular disruption of spinal GABAergic system in rats. ⋯ The drug did not attenuate the responses of UBD-sensitive pelvic nerve afferent (PNA) fibers to UBD and SI in either group of rats tested. Immunohistochemical studies showed a significantly lower level of GABAAα-2 receptor expression in the LS spinal cord of neonatally zymosan-treated rats compared to saline-treated rats. These findings indicate that neonatal bladder inflammation leads to functional and molecular alteration of spinal GABAAα-2 receptor subtypes, which may result in chronic visceral hyperalgesia in adulthood.