Sensory cortices do not work in isolation. The functional responses of neurons in primary sensory cortices can be affected by activity from other modalities. For example, short-term visual deprivations, or dark exposure (DE), leads to enhanced neuronal responses and frequency selectivity to sounds in layer 4 (L4) of primary auditory cortex (A1). Circuit changes within A1 likely underlie these c...

OBJECTIVE To identify the correlations between the location of multifidus atrophy and the level of lumbar radiculopathy. METHODS Thirty-seven patients who had unilateral L4 or L5 radiculopathy were divided into 2 groups; the L4 radiculopathy (L4 RAD) group and the L5 radiculopathy (L5 RAD) group. Bilateral lumbar multifidus muscles at the mid-spinous process level of L4 vertebra (L4 MSP), the...

During active somatosensation, neural signals expected from movement of the sensors are suppressed in the cortex, whereas information related to touch is enhanced. This tactile suppression underlies low-noise encoding of relevant tactile features and the brain's ability to make fine tactile discriminations. Layer (L) 4 excitatory neurons in the barrel cortex, the major target of the somatosenso...

Ribosome-inactivating proteins (RIPs) are rRNA N-β-glycosidases (EC number 3.2.2.22) widespread in plants, where they play a role in defence against external pathogens. They are able to inhibit protein biosynthesis in pathogens by inactivating their ribosomes through a site-specific deadenylation of the large ribosomal RNA [1]. In recent years, their cytotoxicity has been exploited for the deve...

In neocortex, the induction and expression of long-term potentiation (LTP) and long-term depression (LTD) vary depending on cortical area and laminae of presynaptic and postsynaptic neurons. Layer 4 (L4) is the initial site of sensory afference in barrel cortex and primary visual cortex (V1) in which excitatory inputs from thalamus, L6, and neighboring L4 cells are integrated. However, little i...

Nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) are two major members of the neurotrophin family. Using immunohistochemistry and in situ hybridization histochemistry, we examined the effect of L5 spinal nerve ligation (SPNL), a neuropathic pain model, on the expression of BDNF in the uninjured L4 dorsal root ganglion (DRG). After L5 SPNL, both immunoreactivity for BDNF an...

OBJECTIVE To correlate spinopelvic balance with the development of degenerative spondylolisthesis and disk herniation. METHODS This was a descriptive retrospective study that evaluated 60 patients in this hospital, 30 patients with degenerative spondylolisthesis at the L4-L5 level and 30 with herniated disk at the L4-L5 level, all of whom underwent Surgical treatment. RESULTS Patients with ...

A 56-year-old alcoholic male incurred L5 vertebral body and bilateral L4 pars fractures with progressive L4 on L5 anterolisthesis following low-energy falls while intoxicated. Recently, he had a L3-S1 laminectomy for lumbar spinal stenosis with claudication. Preoperative imaging and radiographs were negative for pars defects and instability, so an isolated decompressive surgery was performed. F...

We present a case of an anomalous accessory iliacus muscle in the iliac fossa which gets originated from the iliac crest and inserting along with iliopsoas, and appear to compress the L4 root of femoral nerve. During the routine dissection of a male cadaver aged 58 years, we found an accessory iliacus muscle. The L2 and L3 nerve roots joined the L4 root distal to the accessory iliacus muscle. T...

Thalamocortical (TC) connectivity is reorganized by thalamic inputs during postnatal development; however, the dynamic characteristics of TC reorganization and the underlying mechanisms remain unexplored. We addressed this question using dendritic refinement of layer 4 (L4) stellate neurons in mouse barrel cortex (barrel cells) as a model; dendritic refinement of L4 neurons is a critical compon...