Sustained potassium current appears later than transient potassium current. During the early stages of rapid dendritic growth, sodium-dependent action potentials are broadened

by a calcium component. Narrowing of spike shape coincides with sequential increases in transient and sustained potassium currents during stages when dendritic growth ceases. Targeted RNAi knockdown of pupal calcium current significantly reduces dendritic growth. These data indicate that the stereotyped sequential acquisition of different voltage-gated H 89 research buy ion channels affects spike shape and excitability such that activity-dependent calcium influx serves as a partner of genetic programs during critical stages of motoneuron dendrite growth. “
“Lysosomal storage disorders are a large group of inherited metabolic conditions resulting from the deficiency of proteins involved in lysosomal catabolism, with resulting ALK inhibitor accumulation

of substrates inside the cell. Two-thirds of these disorders are associated with a neurodegenerative phenotype and, although few therapeutic options are available to patients at present, clinical trials of several treatments including lysosomal enzyme replacement are underway. Although animal studies indicate the efficacy of pre-symptomatic treatment, it is largely unknown whether symptomatic disease-related pathology and functional deficits are reversible. To begin to address this, we used a naturally-occurring mouse model with Sanfilippo syndrome (mucopolysaccharidosis type IIIA) to examine the effectiveness of intracisternal DNA ligase cerebrospinal fluid enzyme replacement in early, mid- and symptomatic

disease stage mice. We observed a disease-stage-dependent treatment effect, with the most significant reductions in primary and secondary substrate accumulation, astrogliosis and protein aggregate accumulation seen in mucopolysaccharidosis type IIIA mice treated very early in the disease course. Affected mice treated at a symptomatic age exhibited little change in these neuropathological markers in the time-frame of the study. Microgliosis was refractory to treatment regardless of the age at which treatment was instigated. Although longer-term studies are warranted, these findings indicate the importance of early intervention in this condition. “
“Nax, a sodium concentration-sensitive sodium channel, is expressed in non-myelinating Schwann cells of the adult peripheral nervous system, but the pathophysiological role remains unclear. We found that functional recovery of the hind paw responses from the sciatic nerve transection was delayed in Nax knockout ( ) mice. Histological analyses showed a decrease in the number of regenerated myelinated axons in sciatic nerves. The delay in the recovery in mice was improved by lactate and inhibited by a monocarboxylate transporter inhibitor.