CP-96,345, a nonpeptide substance P antagonist, is selective for the tachykinin NK1 receptor. The compound binds to single population of sites in guinea pig brain and potently inhibits P-induced excitation locus ceruleus neurons. CP-96,345 should be useful tool studying action central nervous system.

One of the major challenges faced by developing visual system is how to stably process information, yet at same time remain flexible enough accommodate growth and plasticity induced experience. We find that in Xenopus retinotectal circuit, during a period development when map undergoes activity-dependent refinement inputs strengthen, tectal neurons adapt their intrinsic excitability such stable relationship between total level synaptic input neuron spike output conserved. This homeostatic...

The optic tectum is central for transforming incoming visual input into orienting behavior. Yet it not well understood how this behavior organized early in development and relates to the response properties of developing system. We designed a novel behavioral assay study visually guided Xenopus laevis tadpoles. found that, during development, avoidance-an innate, tectally mediated behavior-is tuned specific stimulus size sensitive changes contrast. Using vivo recordings we that developmental...

We assayed glutamate transport activity in cultures of rat cortical neurons containing &lt;0.2% astrocytes. Using [³H]l-glutamate as the tracer, sodium-dependent high affinity was demonstrated [<i>K</i>_<i>m</i> = 17.2 ± 2.4 μm; <i>V</i>_max 3.3 0.32 nmol/mg protein/min (<i>n</i> 5)]. Dihydrokainate (1 mm) inhibited uptake radioactivity by 88 3% and had a<i>K</i>_<i>i</i> value 65 7 μm. l-α-Aminoadipate only 25 4%.l-<i>trans</i>-2,4-Pyrrolidine...

Abstract Background Fragile X Syndrome is the leading monogenetic cause of autism and most common form intellectual disability. Previous studies have implicated changes in dendritic spine architecture as primary result loss Mental Retardation Protein (FMRP), but recent work has shown that neural proliferation decreased cell death increased with either FMRP or overexpression FMRP. The purpose this study was to investigate effects on behavior cellular activity. Methods We knocked down...

With a multitude of substrates, γ-secretase is poised to control neuronal function through variety signaling pathways. Presenilin 1 (PS1) an integral component and also protein closely linked the etiology Alzheimer's disease (AD). To better understand roles PS1 in normal pathological synaptic transmission, we examined evoked spontaneous neurotransmitter release cultured hippocampal neurons derived from knock-out (KO) mice. We found no changes size currents, short-term plasticity, or apparent...

Mesencephalic trigeminal (M-V) neurons are primary somatosensory with somata located within the CNS, instead of in peripheral sensory ganglia. In amphibians, these unipolar cells found optic tectum and have a single axon that runs along mandibular branch nerve. The has collaterals brain stem is believed to make synaptic contact motor nucleus, forming part sensorimotor loop. number M-V known increase until metamorphosis then decrease, suggesting at least some may play transient role during...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis, in vitro binding profile, and autoradiographic analysis of [3H]-cis-3-[(2-methoxybenzyl)amino]-2-phenylpiperidine, a highly potent selective nonpeptide substance P receptor antagonist radioligandTerry Rosen, Thomas F. Seeger, Stafford McLean, Manoj C. Desai, Karen J. Guarino, Dianne Bryce, Kara Pratt, James Heym, Philip M. Chalabi, Cite this: Med. Chem. 1993, 36, 21, 3197–3201Publication Date (Print):October 1, 1993Publication History...

Across the rostrocaudal (RC) axis of Xenopus tadpole optic tectum exists a developmental gradient. This gradient has served as useful model to study many aspects synapse and dendrite maturation. To compliment these studies, we characterized how intrinsic excitability, ease in which neuron can fire action potentials, might also be changing across same axis. Whole-cell recordings from tectal neurons at different points along RC revealed graded increase excitability: compared with caudal end...

Many animals, especially those that develop externally, are equipped with innate color preferences promote survival. For example, Xenopus tadpoles known to phototax most robustly towards mid-spectrum ("green") wavelengths of light while avoiding shorter ("blue") wavelengths. The preference green likely promotes survival by guiding the aquatic plants – their source both food and safety. Here, we characterize dynamics circuitry give rise this intriguing hard-wired behavior. Using a novel...

It is well established that, during neural circuit development, glutamatergic synapses become strengthened via NMDA receptor (NMDAR)-dependent upregulation of AMPA (AMPAR)-mediated currents. In addition, however, it known that the neuromodulator serotonin present throughout most regions vertebrate brain while are forming and being shaped by activity-dependent processes. This suggests may modulate or contribute to these Here, we investigate role in developing retinotectal projection Xenopus...

As the catalytic component of γ-secretase, presenilin (PS) has long been studied in context Alzheimer's disease through cleaving amyloid precursor protein. PS/γ-secretase, however, also cleaves a multitude single-pass transmembrane proteins that are important during development, including Notch, netrin receptor DCC, cadherins, drebrin-A, and EphB2 receptor. Because transgenic PS-KO mice do not survive to birth, studies this molecule later embryonic or early postnatal stages development have...

In the vertebrate CNS, afferent sensory inputs are targeted to specific depths or layers of their target neuropil. This patterning exists ab initio, from very beginning, and therefore has been considered an activity-independent process. However, here we report that, during circuit development, subcellular segregation visual mechanosensory regions tectal neuron dendrites in tadpole optic tectum requires NMDA receptor activity. Blocking NMDARs formation these circuits, removing set inputs,...

Abstract Changes in connectivity between pairs of neurons can serve as a substrate for information storage and experience‐dependent changes neuronal circuitry. Early development, synaptic contacts form break, but how these dynamics influence the is not known. Here we used time‐lapse imaging to examine interactions cultured cortical pyramidal neurons, found that axon–dendrite each pair were composed both relatively stable more labile population. Under basal conditions, loss gain within this...

In many regions of the vertebrate brain, microcircuits generate local recurrent activity that aids in processing and encoding incoming afferent inputs. Local can amplify, filter, temporally spatially parse out input. Determining how these function is great interest because it provides glimpses into fundamental processes underlying brain computation. Within Xenopus tadpole optic tectum, deep layer neurons display robust activity. Although development plasticity this has been well described,...

Innate visually guided behaviors are thought to promote survival by guiding organisms sources of food and safety away from harm without requiring learning. Historically, innate have been considered hard-wired invariable, but emerging evidence shows that many flexible complex due modulation. Here, we investigate the modulation preference for light displayed Xenopus laevis tadpole, an exceptionally invasive well-studied organism is known display several different behaviors. We found tadpoles a...

The Xenopus tadpole optic tectum is a multisensory processing center that receives direct visual input as well nonvisual mechanosensory input. tectal neurons comprise the are organized into layers. These project their dendrites laterally neuropil where inputs target distal region of dendrite and proximal same dendrite. popular model to study development sensory circuits. However, whole cell patch-clamp electrophysiological studies (using brain or in vivo preparations) have focused solely on...