Neuroscience letters
-
Neuroscience letters · Sep 2004
Development of neuropathic pain is affected by bedding texture in two models of peripheral nerve injury in rats.
It has long been known that there are numerous genetic and environmental factors that affect the in vivo research of neuropathic pain. In this letter, we describe the impact that bedding material can have on the development of neuropathic pain behaviors in rodents. ⋯ Rats housed on coarse sawdust presented with a much-reduced response to a pinprick and acetone test compared to counterparts housed on fine sawdust. It is therefore concluded that the development of specific stimulus modalities of neuropathic pain behavior following peripheral nerve injury can be influenced in part by environmental factors, in this case bedding texture.
-
Neuroscience letters · Sep 2004
Comparative StudyImpairment of a cortical event-related desynchronisation during a bimanual load-lifting task in children with autistic disorder.
In autism, the abilities of communication are affected, associated with abnormalities of cognitive, sensorial and motor development. In a previous study based on a load-lifting task, we showed impairment of anticipation in children with autism as evidenced by kinematics and eletromyographic recordings [Neurosci. Lett. 348 (2003) 17]. ⋯ This indicates that the ERD can also translate the use of anticipatory postural adjustments. By contrast, children with autism did not show an ERD in the two voluntary situations. This suggests a central deficit of anticipation in both postural and motor control in children with autism.
-
Neuroscience letters · Sep 2004
Comparative StudyEffect of voluntary contraction intensity on the H-reflex and V-wave responses.
This study examined the evolution of H-reflex and V-wave responses of soleus muscle during maximal voluntary plantar-flexor contraction. We also investigated the relationship between the V response and force level and between V-wave during maximal voluntary contraction (MVC) and the maximal H reflex at rest. The H-reflex and the V-wave responses are measures of motoneuron excitability and also reflect the magnitude of presynaptic inhibition on Ia afferents and the magnitude of descending motor drive. ⋯ V/Msup and Hmax/Mmax were linearly correlated (r2 = 0.81), but V/Msup was significantly lower (P < 0.01) than Hmax/Mmax. In conclusion, the present study shows that maximal voluntary contractions potentiate some reflex responses. The V wave, which reflects motoneuron excitability presynaptic inhibition of Ia afferents and the magnitude of descending central motor drive to spinal motoneurons, may be a relatively simple method to analyse the modulation adaptive neural alterations at spinal and supraspinal level during voluntary contractions.
-
Neuroscience letters · Sep 2004
Comparative StudyEffects of Chlorpheniramine and L-histidine on vestibular compensation in goldfish, Carassius auratus.
Histamine is thought to be involved in the recovery of vestibular function after damage to the vestibular receptors of the inner ear. This study evaluated the effects of post-operative treatment using Chlorpheniramine (H1 histamine antagonist) and L-histidine, (a histaminergic precursor), after hemilabyrinthectomy in goldfish. In this lesion model, the unilateral removal of the labyrinth induces a transient postural imbalance in response to light. ⋯ Another group, which served as a non-lesion control, did not receive hemilabyrinthectomy or systemic injections. Chlorpheniramine accelerated the functional recovery when compared with that of the saline group. These data suggest that the inhibition of the histaminergic system facilitates the functional recovery in goldfish.
-
Neuroscience letters · Sep 2004
Comparative StudyEffect of simple spike firing mode on complex spike firing rate and waveform in cerebellar Purkinje cells in non-anesthetized mice.
Cerebellar Purkinje cells receive two different excitatory inputs from parallel and climbing fibers, causing simple and complex spikes, respectively. Purkinje cells present three modes of simple spike firing, namely tonic, silent and bursting. The influence of complex spike firing on simple spike firing has been extensively studied. ⋯ This alteration is a specific decrement of the second depolarizing component of the complex spike. We demonstrate that the amplitude of the second depolarizing component is inversely proportional to the simple spike firing rate preceding the complex spike and that this amplitude is independent of previous complex spike firing. This waveform modulation is different from previously reported modulation in paired-pulse depression and refractoriness.