OBJECTIVE: Electrophysiological studies, which are mostly focused on afferent pathway, have proven that auditory processing deficits exist in patients with schizophrenia. Nevertheless, reports on the suppressive effect of efferent auditory pathway on cochlear outer hair cells among schizophrenia patients are limited. The present, case-control, study examined the contralateral suppression of transient evoked otoacoustic emissions (TEOAEs) in patients with schizophrenia. METHODS: Participants were twenty-three healthy controls and sixteen schizophrenia patients with normal hearing, middle ear and cochlear outer hair cells function. Absolute non-linear and linear TEOAEs were measured in both ears by delivering clicks stimuli at 80 dB SPL and 60 dB SPL respectively. Subsequently, contralateral suppression was determined by subtracting the absolute TEOAEs response obtained at 60 dBpe SPL during the absence and presence of contralateral white noise delivered at 65 dB HL. No attention tasks were conducted during measurements. RESULTS: We found no significant difference in absolute TEOAEs responses at 80 dB SPL, in either diagnosis or ear groups (p>0.05). However, the overall contralateral suppression was significantly larger in schizophrenia patients (p<0.05). Specifically, patients with schizophrenia demonstrated significantly increased right ear contralateral suppression compared to healthy control (p<0.05). CONCLUSION: The present findings suggest increased inhibitory effect of efferent auditory pathway especially on the right cochlear outer hair cells. Further studies to investigate increased suppressive effects are crucial to expand the current understanding of auditory hallucination mechanisms in schizophrenia patients.
Afferent Pathways ; Auditory Pathways ; Case-Control Studies ; Diagnosis ; Ear ; Ear, Middle ; Efferent Pathways ; Hair ; Hallucinations ; Hearing ; Humans ; Noise ; Schizophrenia*

Afferent Pathways ; Animals ; Female ; Nerve Block ; Olfactory Bulb ; metabolism ; Parvalbumins ; metabolism ; Rats ; Rats, Wistar

No abstract available.
Afferent Pathways ; Fecal Incontinence

Impaired or blunted rectal sensation, termed rectal hyposensitivity (RH), which is defined clinically as elevated sensory thresholds to rectal balloon distension, is associated with disorders of hindgut function, characterised primarily by symptoms of constipation and fecal incontinence. However, its role in symptom generation and the pathogenetic mechanisms underlying the sensory dysfunction remain incompletely understood, although there is evidence that RH may be due to 'primary' disruption of the afferent pathway, 'secondary' to abnormal rectal biomechanics, or to both. Nevertheless, correction of RH by various interventions (behavioural, neuromodulation, surgical) is associated with, and may be responsible for, symptomatic improvement. This review provides a contemporary overview of RH, focusing on diagnosis, clinical associations, pathophysiology, and treatment paradigms.
Afferent Pathways ; Biomechanics ; Constipation ; Fecal Incontinence ; Sensation ; Sensory Thresholds

OBJECTIVETo investigate the role of the dorsal column (DC) in the inhibitory effect of somatic afferent inputs on the central pressor response.

METHODSThe femoral arterial pressure, mean arterial pressure (MAP), electrocardiogram (ECG) and heart rate (HR) of the male SD rats were recorded when the hypothalamic paraventricular nucleus (PVN) was electrically stimulated with or without destruction of DC. The inhibitory effect of the deep peroneal nerve (DPN) on the pressor response induced by stimulation of PVN was observed 20 min or 5 d after ipsilateral DC destruction.

RESULTSStimulating DPN inhibited the pressor response elicited by electrical stimulation of PVN with an inhibitory rate of 43.29%. Twenty minutes after destroying the right DC, stimulation of the right or left DPN could inhibit the pressor response with an inhibitory rate of 38.64% and 39.97%, respectively (P>0.05); five days later the inhibitory rates remained as 33.87% and 36.86% respectively (P>0.05). The pain responses of both hindlimbs in the rats with the right DC destroyed showed no significant difference compared with the intact rats.

CONCLUSIONDC is not involved in the inhibitory effect of DPN on the pressor response induced by PVN stimulation.

Afferent Pathways ; physiology ; Animals ; Blood Pressure ; physiology ; Electric Stimulation ; Male ; Paraventricular Hypothalamic Nucleus ; physiology ; Peroneal Nerve ; physiology ; Pressoreceptors ; physiology ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Spinal Cord ; physiology ; Spinothalamic Tracts ; physiology

AIMTo explore the influence of GABAergic neurotransmitters and GABAA receptors on the auditory afferent impulses recorded in the brainstem evoked by electro-stimulation.

METHODSBrainstem slices were prepared using ddy/ddy mice of postnatal 0-5th days. The brainstem slices were stained with a voltage-sensitive dye(NK3041). The cut end of the vestibulocochlear nerve (nVIIIth) connected with slices was stimulated by a tungsten electrode, a 16 x 16 pixels silicon photodiode array apparatus was used to record the optical mapping from auditory brainstem slices. The data were analyzed by ARGUS-50/PDA software.

RESULTSThe spatial-temporal patterns of the excitatory propagation from the vestibulocochlear nerve (nVIIIth) to cochlear nucleus and vestibular nucleus were displayed with multiple-sites optical recording. The optical signal coming from one pixel consisted of a fast spike-like response and a following slow response. Inhibitory neurotransmitter GABA decreased the fast spike-like response and following slow response of evoked optical signals, while an antagonist BMI against GABAA receptors increased the both responses.

CONCLUSIONA 16 x 16 pixel silicon photodiode array apparatus can be used to record multiple-sites optical mapping evoked by electro-stimulation to the cut end of the vestibulocochlear nerve. The every optical signal consists of both presynaptic and postsynaptic elements. Inhibitory neurotransmitter GABA and an antagonist BMI of GABAA receptors can modulate the excitatory propagation of evoked optical signals.

Animals ; Animals, Newborn ; Auditory Pathways ; physiology ; Brain Stem ; physiology ; Evoked Potentials, Auditory, Brain Stem ; physiology ; In Vitro Techniques ; Mice ; Neurons, Afferent ; physiology ; Optics and Photonics ; Photic Stimulation ; Receptors, GABA-A ; physiology ; gamma-Aminobutyric Acid ; physiology

The purpose of the present study is to find out whether the ophthalmotonic consensual reaction really exists and through what channel the reaction is brought about in rabbits. Twenty-eight pigmented male rabbits were divided into four groups of seven rabbits each, and the intraocular pressure of each eye was measured at designated times in each group with a Mueller electronic tonometer under topical anesthesia (0.5% tetracaine hydrochloride). Retrobulbar anesthesia and compression were performed in each group as follows: Group 1: From 56 minutes to 60 minutes after the experiment had begun, the right eye was compressed for 4 minutes with a 50 gm weight by means of a Baillart ophthalmodynamometer Group 2: About one hour after the experiment had begun, 1.0 cc of 2% procaine hydrochloride was given by retrobulbar injection on the right side. Digital massage after retrobulbar injection was avoided and epinephrine was not employed, because they might influence the intraocular pressure. Group 3: After retrobulbar anesthesia had been performed for the right eye at 40 minutes, this eye was compressed by the above described method from 85 minutes to 90 minutes after the experiment had begun. Group 4: After retrobulbar anesthesia had been performed in the left eye at 40 minutes, the right eye was compressed by the above described method from 86 minutes to 90 minutes after the experiment had begun. The data of each experimental group were analyzed statistically by means of the t-test. Four groups of tonometric studies were done with the following results: 1. After the right eye had been compressed with a 50 gm, weight for 4 minutes, the right intraocular pressure was found to be lowered and then immdiately elevated. The intraocular pressure in the left eye was lowered beginning about 20 minutes after the right eye compression, and this phenomenon may be considered as the ophthalmotonic consensual reaction. 2. After retrobulbar anesthesia with 1.0 cc of 2% procaine hydrochloride had been performed for the right eye, the intraocular pressure was found to be lowered, but that of the left eye showed a slight rise and maintenance of the elevated pressure. 3. When the right eye was compressed after retrobulbar anesthesia had been performed, the grade of rising of the intraocular pressure was lower than when retrobulbar anesthesia had not been performed. The intraocular pressure in the left eye showed no significant change, so it can be postumted that the afferent pathway of the ophthalmotonic consensual reaction was blocked by the retrobulbar anesthesia in the compressed right eye. 4. When the right eye was compressed after retrobulbar anesthesia had been performed previously in the left eye, the change of the intraocular pressure in the right eye showed no difference as when retrobulbar anesthesia had not been performed in the left eye. The intraocular pressure in the left eye showed a similar change as when the right eye had not been compressed, so it can be postulated that the efferent pathway of the ophthalmotonic consensual reaction was blocked by the retrobulbar anesthesia in the non-compressed left eye.
Afferent Pathways ; Anesthesia ; Efferent Pathways ; Epinephrine ; Humans ; Intraocular Pressure ; Male ; Massage ; Procaine ; Rabbits* ; Tetracaine

Afferent Pathways ; anatomy & histology ; Animals ; Female ; Ganglia, Spinal ; anatomy & histology ; Neurons, Afferent ; Rats ; Rats, Sprague-Dawley ; Urinary Bladder ; innervation

BACKGROUND AND OBJECTIVES: Fos, the protein product of c-fos gene, has been known to be rapidly expressed in neurons following various external and internal stimuli and this protein expression has been used as a neural activation marker in many fields. This experiment was performed to examine the afferent pathway of the lateral semicircular canals following sinusoidal acceleration. MATERIALS & METHODS: To stimulate the lateral semicircular canals, animals received rotary stimulation for 90 minutes with 2.0Hz sinusoidal acceleration. Thirty minutes after stimulation, the subjects were sacrificed and their brainstems were processed for immunohistochemistry to detect Fos expression. RESULTS: Fos proteins were strongly expressed in the superior, dorsal medial vestibular and inferior vestibular nuclei. However, there was no expression in the lateral and ventral portion of medial vestibular nuclei. CONCLUSION: This finding suggested that the afferent pathway from peripheral vestibular end-organ can be successfully mapped by detection of Fos expression and Fos is an useful neural activity marker in the vestibular system.
Acceleration* ; Afferent Pathways ; Animals ; Brain Stem* ; Genes, fos ; Immunohistochemistry ; Neurons ; Semicircular Canals ; Vestibular Nuclei*

In this study, the expressions of growth hormone secretagogue receptor type 1a (GHS-R1a) in the rat dorsal root ganglion (DRG) and nodose ganglion (NG) were investigated by using immunohistochemistry and in situ hybridization. The results clearly showed the presence of GHS-R1a mRNA and GHS-R1a-positive neurons in the rat DRG and NG. GHS-R1a was also co-localized with calcitonin gene-related peptide (CGRP) in some DRG and NG neurons, indicating the existence of subpopulations of the visceral afferents. The extrinsic primary afferent visceroceptive DRG and NG neurons from the stomach were identified by retrograde tracing fluorogold and stained for GHS-R1a and CGRP. Some neurons both positive for CGRP and GHS-Rla were labled by fluorogold. Our results not only demonstrate the expression of GHS-R1a in the vagal afferents but also provide the first and direct morphological evidence for its presence in the spinal visceral afferents, and gherin might have a modulatory role in the visceral afferent signaling.
Afferent Pathways ; Animals ; Calcitonin Gene-Related Peptide ; metabolism ; Ganglia, Spinal ; cytology ; Immunohistochemistry ; Neurons, Afferent ; cytology ; Nodose Ganglion ; cytology ; Rats ; Receptors, Ghrelin ; metabolism ; Stomach ; innervation