Damage to the corticospinal tract is a leading cause of motor disability, for example in stroke or spinal cord injury. Some function usually recovers, but whether plasticity of undamaged ipsilaterally descending corticospinal axons and/or brainstem pathways such as the reticulospinal tract contributes to recovery is unknown. Here, we examined the connectivity in these pathways to motor neurons ...

We studied the involvement of deep cortical layer neurons in processing callosal information in the rat. We observed with electron microscopy that both parvalbumin (PV)-labeled profiles and unlabeled dendritic spines of deep cortical layer neurons receive synapses from the contralateral hemisphere. Stimulation of callosal fibers elicited monosynaptic excitatory postsynaptic currents in both lay...

Acetylcholine (ACh), acting at muscarinic ACh receptors (mAChRs), modulates the excitability and synaptic connectivity of hippocampal pyramidal neurons. CA1 pyramidal neurons respond to transient ("phasic") mAChR activation with biphasic responses in which inhibition is followed by excitation, whereas prolonged ("tonic") mAChR activation increases CA1 neuron excitability. Both phasic and tonic ...

GABAergic interneurons in the hippocampus express high levels of alpha7 nicotinic acetylcholine receptors, but because of the diverse roles played by hippocampal interneurons, the impact of activation of these receptors on hippocampal output neurons (i.e., CA1 pyramidal cells) is unclear. Activation of hippocampal interneurons could directly inhibit pyramidal neuron activity but could also prod...

objective(s):growing evidence indicates that extract of ginkgo biloba (egb) attenuates hippocampal-dependent memory deficit in aged individuals; however, very little is known about the effect of egb on the structure of hippocampus. therefore we examined the egb-induced morphological changes of the cornu ammonis (ca) region in aged rats. materials and methods: sixteen aged male wistar rats, 24 m...

Neuropathic pain is a debilitating condition for which the development of effective treatments has been limited by an incomplete understanding of its molecular basis. The cationic current Ih mediated by hyperpolarization-activated cyclic nucleotide-gated (HCN) channels plays an important role in pain by facilitating ectopic firing and hyperexcitability in DRG neurons, however little is known re...

Recent behavioral studies indicate that conditioned fear response to contextual stimuli is reduced effectively by anxiolytic 5-hydroxytryptame (5-HT)1A agonists. Since the hippocampus seems to play an essential role in associative fear memories evoked by context, it is important to assess the effect of 5-HT1A agonists on pyramidal cell activity in the hippocampus. We examined the effects of 5-H...

KCNQ2 and KCNQ3 potassium channels have emerged as central regulators of pyramidal neuron excitability and spiking behavior. However, despite an abundance of evidence demonstrating that KCNQ2/3 heteromers underlie critical potassium conductances, it is unknown whether KCNQ2, KCNQ3, or both are obligatory for maintaining normal pyramidal neuron excitability. Here, we demonstrate that conditional...

background and objective: as one of the widely used drugs, aspirin (acetyl-salicylic acid, asa) plays an important role in stroke treatment and prevention. in a previous study, we demonstrated asa injection at 30 min after ischemia onset is neuroprotective. to determine whether the neurons protected by asa had a normal ultrastructure, hippocampal ca1 pyramidal neurons were examined by transmiss...

Hippocampus as a whole has the shape of a curved tube including CA1-CA4 regions with a single layer of densely packed pyramidal neurons which curl into a tight “U” shape. One edge of the “U”, field CA4, is embedded into a backward facing strongly flexed V-shaped cortex, the dentate gyrus (DG) which comprises molecular, granular, subgranular cell layers and poly-morph layer called hilus (Figure ...