Search results for "Neural"

2020

Motor control is associated with suppression of oscillatory activity in alpha (8–12 Hz) and beta (12–30 Hz) ranges and elevation of oxygenated hemoglobin levels in motor-cortical areas. Aging leads to changes in oscillatory and hemodynamic brain activity and impairments in motor control. However, the relationship between age-related changes in motor control and brain activity is not yet fully understood. Therefore, this study aimed to investigate age-related and task-complexity-related changes in grip force control and the underlying oscillatory and hemodynamic activity. Sixteen younger [age (mean ± SD) = 25.4 ± 1.9, 20–30 years] and 16 older (age = 56.7 ± 4.7, 50–70 years) healthy men were…

Neuronal nicotinic receptors in synaptic functions in humans and rats: physiological and clinical relevance.

2000

The present report describes the participation of nicotinic receptors (nAChRs) in controlling the excitability of local neuronal circuitries in the rat hippocampus and in the human cerebral cortex. The patch-clamp technique was used to record responses triggered by the non-selective agonist ACh and the alpha7-nAChR-selective agonist choline in interneurons of human cerebral cortical and rat hippocampal slices. Evidence is provided that functional alpha7- and alpha4beta2-like nAChRs are present on somatodendritic and/or preterminal/terminal regions of interneurons in the CA1 field of the rat hippocampus and in the human cerebral cortex and that activation of the different nAChR subtypes pres…

Locomotor and antidepressant-like effects of 5-HT(1A) agonist LY 228729 in prenatally benzodiazepine-exposed rats.

1998

Locomotor activity and antidepressant-like effect in the forced swim test (FST) of 5-HT(1A) agonist LY 228729 were investigated in adult rats prenatally exposed at doses of diazepam (DZ) and alprazolam (ALP) which induce persistent downregulation of GABA/ benzodiazepine (BZ) receptors. Prenatal exposure to ALP and DZ did not modify the efficacy of subchronic LY 228729 to decrease immobility time in the FST. Prenatal DZ and ALP potentiated the facilitatory effect of subchronic LY 228729 on locomotor activity; prenatal DZ was more effective than prenatal ALP. Moreover, prenatal DZ increased stereotypic movements induced by LY 228729. These data suggest that the persistent downregulation of GA…

Involvement of tachykinin NK2 receptors in the modulation of spontaneous motility in rat proximal colon.

2000

The role of endogenous tachykinins and the mechanisms whereby they act on NK2 receptors, modulating spontaneous motility, were investigated in rat isolated proximal colon. The mechanical activity was detected as changes in intraluminal pressure. The NK2 receptor antagonist, MEN 10627, produced a concentration-dependent reduction of the contraction amplitude. [beta-Ala8]-neurokinin A(4-10), an NK2 receptor agonist, and [Sar9, Met(O2)11]-Substance P ([Sar9, Met(O2)11]-SP), an NK1 receptor agonist, induced a concentration-dependent contractile response, characterized by an increase in basal tone with superimposed phasic contractions. MEN 10627 antagonized the response to [beta-Ala8]-neurokinin…

Modulatory effects of the novel TrkB receptor agonist 7,8-dihydroxyflavone on synaptic transmission and intrinsic neuronal excitability in mouse visu…

2013

7,8-Dihydroxyflavone (7,8 DHF) is a new recently identified TrkB receptor agonist, which possesses a potent neurotrophic activity and shares many physiological properties with the neurotrophin "Brain Derived Neurotrophic Factor" (BDNF). However, its precise mechanism of action at the cellular level has not been clarified yet. In the present study we explored the effects of this agent on synaptic and intrinsic neuronal properties by performing whole-cell patch clamp recordings from layer 2/3 pyramidal neurons. Incubation of acute cortical slices with 7,8-DHF (20 µM) for 30 min caused a selective reduction in the strength of GABAergic inhibition. The amplitude of evoked inhibitory postsynapti…

GABA, receptor mediated fast synaptic inhibition in the rabbit brain-stem respiratory system

1991

The involvement of GABA mediated neurotransmission in the central control of respiration was investigated by administration of the specific GABAA receptor agonist muscimol and the specific GABAA receptor antagonist biculline into the fourth cerebral ventricle of the rabbit. Cycle-triggered averaging of the phrenic nerve activity (PNA) was used to quantify drug-induced changes of the central respiratory pattern. Muscimol reduced the peak amplitude of PNA and increased the duration of the respiratory phases. High amounts of muscimol led to a long-lasting but reversible central apnea. Bicuculline very effectively blocked the effects of externally applied muscimol. Blockade of intrinsically act…

THE CAUSAL ROOTS OF INTEGRATION AND THE UNITY OF CONSCIOUSNESS

2016

A fundamental feature of consciousness is unity. The problem is whether unity is compatible both with the physical underpinnings of conscious experience and with the fabric of the physical world in general.

Sign Languages Recognition Based on Neural Network Architecture

2017

In the last years, many steps forward have been made in speech and natural languages recognition and were developed many virtual assistants such as Apple’s Siri, Google Now and Microsoft Cortana. Unfortunately, not everyone can use voice to communicate to other people and digital devices. Our system is a first step for extending the possibility of using virtual assistants to speech impaired people by providing an artificial sign languages recognition based on neural network architecture.

Übertragung von Verhaltensweisen durch Transplantation von Anlagen neuroanatomischer Strukturen bei Amphibienlarven

2010

By replacing parts of the neural plate (prospective medulla oblongata) of Triturus vulgaris by neural ectoderm of Xenopus laevis larval chimaeras were obtained, which showed donorlike rhythmical movements of distinct parts of the visceral musculature according to the place of implantation. Especially the branchial region with its external gills showed rhythmical movements and is the special object of this investigation.

Perineural Invasion is a Strong Prognostic Moderator in Ampulla of Vater Carcinoma

2018

Objective Ampulla of Vater carcinoma (AVC) has a broad spectrum of different prognoses. As such, new moderators of survival are urgently needed. We aimed at clarifying the prognostic role of perineural invasion in AVC. Methods Using PubMed and SCOPUS databases, we conducted the first systematic review and meta-analysis on this topic. Results Analyzing 29 articles for a total of 2379 patients, we found that the presence of perineural invasion increased the risk of all-cause mortality more than 2 times (relative risk [RR], 2.07; 95% confidence interval [CI], 1.78-2.42 [P < 0.0001]; hazard ratio [HR], 2.72; 95% CI, 1.86-3.97 [P < 0.0001]), of cancer-specific mortality more than 6 times (…