Previously, we showed that the ventral premotor cortex (PMv) underwent neurophysiological remodeling after injury to primary motor (M1). In present study, examined cortical connections of PMv such lesions. The neuroanatomical tract tracer biotinylated dextran amine was injected into hand area at least 5 months ischemic M1 area. Comparison labeling patterns between experimental and control animals demonstrated extensive proliferation novel terminal fields appearance retrogradely labeled cell...

Although recent neurological research has shed light on the brain's mechanisms of self-repair after stroke, role that intact tissue plays in recovery is still obscure. To explore these further, we used microelectrode stimulation techniques to examine functional remodeling cerebral cortex an ischemic infarct hand representation primary motor five adult squirrel monkeys. Hand preference and skill both hands were assessed periodically a pellet retrieval task for 3 mo postinfarct. Initial...

Stroke is often characterized by incomplete recovery and chronic motor impairments. A nonhuman primate model of cortical ischemia was used to evaluate the feasibility using device-assisted stimulation combined with rehabilitative training enhance behavioral plasticity. Following pre-infarct on a unimanual task, maps movement representations in primary cortex were derived. Then, an ischemic infarct produced which destroyed hand representation. Several weeks later, second map derived guide...

After a cortical lesion, areas distant from the site of injury are known to undergo physiological and anatomical changes. However, mechanisms through which reorganization is initiated poorly understood. In previous publication, we showed that ventral premotor cortex (PMv) undergoes after lesion destroying majority primary motor (M1) distal forelimb representation (DFL). large lesions >50% M1 DFL, PMv DFL invariably increased in size, amount increase was positively correlated with size...

Neuroimaging studies in stroke survivors have suggested that adaptive plasticity occurs following stroke. However, the complex temporal dynamics of neural reorganization after injury make interpretation functional imaging equivocal. In present study adult squirrel monkeys, intracortical microstimulation (ICMS) techniques were used to monitor changes representational maps distal forelimb supplementary motor area (SMA) a unilateral ischemic infarct primary (M1) and premotor representations...

Motor output capabilities of the forelimb representation dorsal motor area (PMd) and ventral (PMv) were compared with primary cortex (M1) in terms latency, strength, sign, distribution effects. Stimulus-triggered averages (60 μA) electromyographic activity collected from 24 muscles computed at 314 tracks 2 monkeys trained to perform a reach-to-grasp task. The onset latency magnitude facilitation effects PMd PMv significantly longer 7- 9-fold weaker than those M1. Proximal predominantly...

Abstract The present study describes the pattern of connections ventral premotor cortex (PMv) with various cortical regions ipsilateral hemisphere in adult squirrel monkeys. Particularly, we 1) quantified proportion inputs and outputs that PMv distal forelimb representation shares other areas 2) defined respect to location primary motor (M1), somatosensory (S1), supplementary area (SMA). Intracortical microstimulation techniques (ICMS) were used four experimentally naïve monkeys identify M1,...

To examine the potential early stages in evolution of sensorimotor cortex, electrophysiological studies were conducted primitive South American marsupial opossum, Monodelphis domestica. Somatosensory maps derived from multiunit microelectrode recordings revealed a complete somatosensory representation contralateral body surface within large region midrostral cortex (primary or S1). A proportion (∼51%) S1 was devoted to glaborous snout, mystacial vibrissae, lower jaw, and oral cavity (the...

This study was undertaken to determine the topographic organization of connections between forelimb representations ventral premotor cortex (PMv) and primary motor (M1). Intracortical microstimulation techniques were used in three experimentally naive squirrel monkeys delineate M1 PMv hemisphere contralateral dominant hand. Small amounts biotinylated dextran amine (BDA) then injected distal representation. Following tangential sectioning, location injection core BDA-labeled cell bodies...

Vascular endothelial growth factor (VEGF) is thought to contribute both neuroprotection and angiogenesis after stroke. While increased expression of VEGF has been demonstrated in animal models experimental ischemia, these studies have focused almost exclusively on the infarct peri-infarct regions. The present study investigated association neurons remote cortical areas at three days an primary motor cortex (M1). Although are outside direct influence ischemic injury, plasticity implicated...

Abstract This study describes the pattern of interhemispheric connections ventral premotor cortex (PMv) distal forelimb representation (DFL) in squirrel monkeys. Our objectives were to describe qualitatively and quantitatively PMv with contralateral cortical areas. Intracortical microstimulation techniques (ICMS) guided injection neuronal tract tracers biotinylated dextran amine or Fast blue into DFL. We classified three groups. Major found supplementary motor area (SMA). Intermediate...

Abstract Injury of CNS nerve tracts remodels circuitry through dendritic spine loss and hyper-excitability, thus influencing recovery. Due to the complexity CNS, a mechanistic understanding injury-induced synaptic remodeling remains unclear. Using microfluidic chambers separate injure distal axons, we show that axotomy causes retrograde at directly injured pyramidal neurons followed by presynaptic hyper-excitability. These events require activity site injury, axon-to-soma signaling,...

Primary motor cortex (M1) has traditionally been considered a structure. Although neurophysiologic studies have demonstrated that M1 is also influenced by somatosensory inputs (cutaneous and proprioceptive), the behavioral significance of these yet to be fully defined in primates. The present study describes differential sensory-related deficits after small ischemic lesions either rostral or caudal subregion hand area nonhuman primate. Squirrel monkeys retrieved food pellets out different...

Recovery of motor function after stroke is accompanied by reorganization movement representations in spared cortical regions. It widely assumed that map parallels recovery, suggesting a causal relationship. We examined this assumption measuring changes eight male and six female squirrel monkeys the first few weeks injury, time when recovery most rapid. Maps were derived using intracortical microstimulation techniques primary cortex (M1), ventral premotor (PMv), dorsal (PMd) 14 adult before...

Telencephalic projections from the medial geniculate nucleus (MG) in opossum were traced with tritiated leucine autoradiography and by horseradish peroxidase fluorescent dye retrograde labeling techniques. The results show that opossum's MG contains two separate populations of neurons-one anterior two-thirds projecting to auditory neocortex, other occupying entire caudal one-third mostly lateral amygdala putamen. Because subcortical projection is larger than seen any mammal date, it...

Clinical and experimental data support a role for the intact cortex in recovery of function after stroke, particularly ipsilesional areas interconnected to infarct. There is, however, little understanding molecular events cortex, as most studies focus on infarct peri-infarct regions. This study investigated neuronal immunoreactivity hypoxia-inducible factor-1α (HIF-1α) vascular endothelial growth factor (VEGF) receptor-2 (VEGFR-2) remote cortical 3 days focal ischemic infarct, both HIF-1α...

The purpose of this study was to examine neuronal activity levels in the hindlimb area motor cortex following spinal cord injury (SCI) rats and compare results with measurements normal rats. Fifteen male Fischer-344 received a 200 Kdyn contusion thoracic at level T9–T10. After minimum 4 weeks SCI, intracortical microstimulation (ICMS) single-unit recording techniques were used both forelimb areas (FLA, HLA) under ketamine anesthesia. Although movements could be evoked using ICMS relatively...

Objective. Spinal cord injury (SCI) is a devastating neurological trauma with prevalence of about 282 000 people living an SCI in the United States 2016. Advances neuromodulatory devices hold promise for restoring function by incorporating delivery electrical current directly into spinal grey matter via intraspinal microstimulation (ISMS). In such designs, detailed topographic maps outputs are needed to determine ISMS locations eliciting hindlimb movements. The primary goal present study was...

Background. There is growing interest in the use of d-amphetamine (d-AMPH) as a pharmacological treatment to supplement rehabilitative therapy following stroke. Based on success earlier animal models, several clinical studies have demonstrated beneficial effects applying physical rehabilitation while stroke patients are under influence d-AMPH. To begin understand neural mechanisms underlying this promising adjuvant therapy, authors examined single pairing d-AMPH and training motor...