Neuroscience letters
-
Neuroscience letters · Jan 2018
Role of KCNQ2 channels in orofacial cold sensitivity: KCNQ2 upregulation in trigeminal ganglion neurons after infraorbital nerve chronic constrictive injury.
Sensitivity to cooling temperatures often becomes heightened in orofacial regions leading to orofacial cold allodynia/hyperalgesia after chronic trigeminal nerve injury. KCNQ2 channels are involved in controlling excitability of primary afferent neurons and thereby regulate sensory functions under both physiological and pathological conditions. In the present study, we sought to determine whether KCNQ2 channels in trigeminal nerves are involved in regulating orofacial operant behavioral responses to cooling stimulation. ⋯ Interestingly, KCNQ2 channel expression becomes significantly upregulated in TG neurons following the ION-CCI. Our results suggest that KCNQ2 channels are involved in regulating orofacial cold sensitivity. Upregulation of KCNQ2 channels may be a compensatory change in attempting to limit injury-induced trigeminal hyperexcitability.
-
Neuroscience letters · Jan 2018
Longitudinal electrophysiological changes after cervical hemi-contusion spinal cord injury in rats.
To evaluate the longitudinal somatosensory evoked potentials (SEPs) and motor evoked potentials (MEPs) characterization from acute to chronic injury following cervical hemi-contusion spinal cord injury (SCI) in rats, and correlate the MEPs & SEPs to the behavioral outcomes. ⋯ Cervical hemi-contusion SCI led to persistent changes in MEPs & SEPs of the ipsilateral forelimb, ipsilateral impairment in motor function and unilateral cord tissue damage. Reliable electrophysiology assessment was obtained in chronic phase due to unstable MEPs & SEPs of bilateral forelimb immediately after injury, which might reflect the underlying pathological processes. The present study further confirmed the link of the MEPs to the behavioral outcomes, supporting the longitudinal electrophysiology assessment for neurological impairment after SCI.
-
Neuroscience letters · Jan 2018
Graded photochemical spinal cord injury results in chronic hyperalgesia and depression-like behaviour but no anxiety exacerbation in female BALB/c mice.
Neuropathic pain (NP) is present in 40-to-50% of spinal cord injured patients. It tends to chronicity and correlates with lower quality-of-life. Moreover, the role of NP in the eventual exacerbation of anxiety- and depression-like behaviours during its development and chronification in genetically susceptible individuals remains unclear. ⋯ Behavioural data suggest that whilst hyperalgesia associated to SCI does not exacerbate BALB/c anxiety-like behaviours, it may result in depression-like behaviour at SCI chronic phase. Our study demonstrates that chronic central hyperalgesia may exacerbate despair-like behaviour at the SCI chronic phase in a mouse model of high anxiety-related behaviour. This implies that photochemical-SCI may be a suitable model to study the comorbidity between chronic NP and mood disorders.
-
Neuroscience letters · Jan 2018
NMDA receptor dependent changes in c-fos and p-CREB signaling following extinction and reinstatement of morphine place preference.
Neural circuitry comprising the ventral tegmental area, nucleus accumbens (NAc), prefrontal cortex (PFC) and hippocampus (HIP) has a main role in reward phenomena. Previous behavioral studies indicated that intracerebroventricular administration of AP5 (NMDA glutamate receptor antagonist) and CNQX (AMPA/kainate glutamate receptor antagonist) during the extinction and before reinstatement of morphine-induced conditioned place preference (CPP) reduced the extinction period and reinstatement of morphine-CPP. Therefore, in the present study, we tried to evaluate the effect of antagonism of NMDA glutamate receptors on the p-CREB/CREB ratio and c-fos expression in the NAc, PFC and HIP during these two phases of morphine-CPP in male adult albino Wistar rats. ⋯ The results revealed that these two factors decreased by antagonism of NMDA glutamate receptors (different doses of AP5) compared to saline-control group in aforementioned regions. The reduction of molecular markers, especially the p-CREB/CREB ratio, after AP5 administration was more during the extinction period. Therefore, it can be assumed that consolidation and reconsolidation of morphine memory via intra-PFC, -NAc and -HIP NMDA glutamate receptors are in accordance with changes in p-CREB/CREB ratio and c-fos levels.
-
Neuroscience letters · Jan 2018
Randomized Controlled TrialEffects of transcranial direct current stimulation over the supplementary motor area body weight-supported treadmill gait training in hemiparetic patients after stroke.
Transcranial direct current stimulation (tDCS) is used in a variety of disorders after stroke including upper limb motor dysfunctions, hemispatial neglect, aphasia, and apraxia, and its effectiveness has been demonstrated. Although gait ability is important for daily living, there were few reports of the use of tDCS to improve balance and gait ability. The supplementary motor area (SMA) was reported to play a potentially important role in balance recovery after stroke. ⋯ Our findings demonstrated the feasibility and efficacy of tDCS in gait training after stroke. The facilitative effects of tDCS on SMA possibly improved postural control during BWSTT. The results indicated the implications for the use of tDCS in balance and gait training rehabilitation after stroke.