Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Experiments on anesthetized cats with partial lesions of the spinal cord show that reticulospinal pathways in the ventral part of the lateral funiculus take part in the polysynaptic reflex inhibition caused by stimulation of ipsi- and contralateral reticular formation. The reticulofugal volley in the ventrolateral funiculus produced relatively short (up to 7 ms) inhibitory PSP in some motoneurons of the internal intercostal nerve and at the same time long-lasting depression of EPSPs evoked by high-threshold segmentary afferents. This volley also caused inhibitory PSP in segmental interneurons (in 14 out of 91, i.e. 15.5%). The IPSPs lasted no longer than 100 ms, while the segmentary excitatory responses of 21 out of 43 interneurons were depressed for 120-500 ms. The described inhibitory action of the lateral reticulospinal system on segmentary reflex pathways is suggested to be caused by several synaptic mechanisms which do not necessarily include hyperpolarization of spinal neurons. Possible mechanisms of such inhibition are discussed.
 ...
PMID:[Inhibitory influences of reticulospinal fibers of the lateral funiculus on neurons of the reflex arc of the thoracic region of the spinal cord]. 65 98

Activity of neurons in the lateral line lobe was studied by intracellular recording of responses to stimulation of the lateral line nerves and of electroreceptors on the skin surface. Two modes of activation occur for cells responding to inputs from medium receptors. There is a direct monosynaptic input mediated by a single fiber. Short latency of response and antidromic spread from cell to afferent fiber indicate that the mediating synapse is electrotonic. The second input is from a number of additional fibers and is relayed, presumably by the granule cells. At shortest latency this input is disynaptic, probably involving at least one electrotonic synapse. A relay is indicated by heterosynaptic facilitation of the PSP and by pronounced depression with repetitive stimulation. The monosynaptic input may be on the axon. Disynaptic inputs are distributed over the dendrites, and impulses can arise in the dendrites. What appear to be spikes restricted to dendritic regions are often recorded as small brief potentials in the cell body. There is a somatotopic projection of the electroreceptors to the lateral line lobe. The monosynaptic input comes from a specific receptor in the periphery. Strong disynaptic inputs come from a group of receptors generally found anterior, but less commonly posterior or lateral, to the receptor giving rise to the monosynaptic input. Additional inputs that are inhibitory come from surrounding receptors. The inhibition only affects responses to the disynaptic input. The different inputs and multiple sites of impulse initiation must modify the cell's response as compared with the input-output relations that would be obtained with inputs acting on a single summation point. Cells responding to activation of large receptors are infrequent. They are characterized by low threshold, little latency change near threshold, and ability to follow high frequencies of stimulation.
 ...
PMID:Responses of cells of posterior lateral line lobe to activation of electroreceptors in a mormyrid fish. 96 37

We report an autopsy case of a 73 year-old female with idiopathic parkinsonism, characterized pathologically by the wide spread appearance of Lewy bodies (LBs) not only in the pigmented neurons in the midbrain and brainstem but also in the cerebral cortex. Initial symptoms at the age of 62 were finger tremor and gait disturbance, which were followed mainly by mental deterioration, such as regression, dependency, auditory hallucination, depression, emotional incontinence, and a personality change. In the terminal stage, nuchal stiffness in extension, one of the hallmarks of progressive supranuclear palsy, and slow and generalized tremor in all 4 extremities were noted. She died of aspiration pneumonia. The brain was somewhat small and weighed 1100 g after the fixation by formalin. Macroscopical findings included mild cerebral atrophy with mild pial thickening both in the frontal and temporal lobes and slight expansion of the ventricular system. Histopathologically, severe loss of neuronal cells in both the pallidum and Luy's body and moderate loss of large cells in the putamen were noted in addition to the typical findings of Parkinson's disease in the substantia nigra and locus caeruleus including neuronal cell loss, depigmentation, and gliosis. These findings in the basal ganglia were more conspicuous than the two controls of classical Parkinson's disease. The distribution, stainability in the routine methods of staining, and shape of Lewy bodies in the cerebral cortex conformed to those of previous reports. The similar case reports in the literatures do not seem to have paid much attention to the findings of the basal ganglia observed in our case.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:[An autopsy case of idiopathic parkinsonism with numerous Lewy bodies in the cerebral cortex--diffuse Lewy body disease]. 165 48

It is well established that cardiac dysfunction independent of atherosclerosis develops in both humans and animals with diabetes mellitus. The etiology is complex, involving many different processes, one of which may be increased fatty acid utilization and/or a concomitant decrease in glucose utilization by the diabetic heart. We compared control and 6-wk streptozotocin (STZ)-induced diabetic isolated working rat hearts and were able to demonstrate cardiac dysfunction in the diabetic as assessed by depressed heart rate (HR), heart rate peak systolic pressure product (HR.PSP), left ventricular developed pressure (LVDP), and rate of pressure rise (+dP/dt). Paralleling depressed cardiac function in the diabetic were hyperglycemia, hyperlipidemia, and decreased body weight gain compared with age-matched controls. The addition of free fatty acids, in the form of 1.2 mM palmitate, to the isolated working heart perfusate had no effect on either control or diabetic heart function, with the exception of a depressive effect on +dP/dt of diabetic hearts. But diabetic hearts perfused with palmitate-containing perfusate plus the glucose oxidation stimulator dichloroacetate (DCA) showed a marked improvement in function. HR and HR.PSP in spontaneously beating hearts, as well as LVDP and +dP/dt in paced hearts were all restored to control heart values in diabetic hearts perfused in the presence of DCA. Creatine phosphate and ATP levels were similar under all perfusion conditions, thus eliminating energy stores as the limiting factor in heart function. Results indicate that DCA will acutely reverse diabetic cardiac function depression. Therefore glucose oxidation depression in the diabetic heart may be a significant factor contributing to cardiac dysfunction.
 ...
PMID:Effects of free fatty acids and dichloroacetate on isolated working diabetic rat heart. 192 88

Flunarizine hydrochloride (FZ), a calcium entry blockade, has been used nationwide in Japan as a cerebral active vasodilator since October, 1984. The present paper reports 31 cases of FZ-induced Parkinsonism, depression and akathisia, referred to our hospital between October 1986 and September 1988. Out of the 31 patients, four including two with Parkinson's disease and one each with progressive supranuclear palsy and olivopontocerebellar atrophy showed worsening of their parkinsonian symptoms within a few months after FZ administration. The remaining 27 patients (7 males and 20 females) newly developed Parkinsonism after treatment with FZ. Symptoms appeared one week to two years (mean: 6.1 months) after starting FZ of a daily dose of 10 mg. FZ had been used in 6 patients for cerebrovascular episodes confirmed by clinical history or brain CT, and in the remainder, for dizziness, light-headedness, hypertension, amnesia or hypochondric neurotic complaints. Akinesia and bradykinesia progressed rather rapidly after onset, and patients became unambulatory within several months. Symptoms had worsened, and L-dopa, anticholinergic drugs, and bromocriptine had been ineffective until FZ was discontinued. Their Parkinsonism was characterized by marked akinesia, bradykinesia, and moderate rigidity. Masked face was seen in most of them. Tremor was absent at rest, and induced in 12 patients by posture and/or action. Sixteen patients were accompanied by depression, and five, by akathisia. Improvement began several weeks after withdrawal of FZ, and most patients recovered almost completely within a few months although mild rigidity and bradykinesia remained in some.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:[Parkinsonism, depression and akathisia induced by flunarizine, a calcium entry blockade--report of 31 cases]. 258 81

A 72-year-old woman, who had previously been diagnosed as schizophrenic, experienced a year of deterioration in her ability to care for herself. She was variously diagnosed as having parkinsonism, catatonic schizophrenia, atypical psychosis, depression, and dementia before she was appropriately diagnosed as having progressive supranuclear palsy.
 ...
PMID:Progressive supranuclear palsy misdiagnosed as schizophrenia. 286 Feb 4

A hypothesis of the role of autoadrenoreceptors in the processes of synaptic depression, facilitation, PSP amplitude stabilization and amplitude increase with the stimulation frequency growth is described by means of a mathematical model. Synaptic depression is realized by activation of alpha-autoadrenoreceptors, synaptic facilitation--by beta-autoadrenoreceptors activation. A "stable secretion zone" is formed between the autoadrenoreceptor activation curves at which noradrenaline secretion is stabilized. Experimental studies of H3-NA secretion from rats cerebral cortex slices showed that autoadrenoreceptors really form a stable secretion zone. The presence of stable secretion zone provides for self-facilitation and stabilization of H3-NA secretion elicited by 5-fold consecutive K+-depolarizations of slices with time interval 30 min. The absence of the stable secretion zone leads to destabilization of H3-NA secretion. With an increase of the stimulation intensity the curves of autoadrenoreceptors activity and stable secretion zone shift toward high noradrenaline concentrations.
 ...
PMID:[Regulation of the efficacy of adrenergic synaptic transmission by autoadrenoreceptors in rat brain slices]. 303 85

Subcortical dementia occurs both in disorders affecting the basal ganglia (for example, Parkinson's disease, Huntington's disease, and progressive supranuclear palsy) and in a variety of subcortical vascular, infectious, inflammatory, neoplastic, and traumatic conditions. The principal features of subcortical dementia include bradyphrenia, impairment of executive function, recall abnormalities, visuospatial disturbances, depression, and apathy. The syndrome contrasts with dementia of the Alzheimer type in which cortical involvement produces aphasia, combined recall and recognition deficits, and indifference. Electrophysiologic, biochemical, and metabolic studies support a distinction between subcortical and cortical dementias.
 ...
PMID:Psychological dysfunction accompanying subcortical dementias. 328 89

The vibration-sensitivity of larval lamprey Mauthner (Mth) neurones is dependent on behavioural state. Animals are maximally vibration-sensitive when at rest and less so when active or aroused. To demonstrate this effect in freely behaving larvae, we provided repeated vibratory or electrical stimuli to the vestibular labyrinths while animals made transitions between rest and activity. Stimuli which were adequate to elicit Mth spikes 100% of the time in a resting animal (recorded extracellularly from the spinal cord) were consistently subthreshold while the animal was swimming. The same effect was seen in semi-intact preparations, both moving and curarized, while recording intracellularly from Mth cell bodies. Mth vibration-sensitivity decreased abruptly with the onset of 'arousal', defined here by the presence of tonic, descending spinal cord discharge. During arousal, the Mth soma exhibited a slight depolarization (2-8 mV), an increased membrane conductance, and a strong depression of vibration-evoked excitatory postsynaptic potential (EPSP) amplitude. This Mth PSP depression (MPD) appears to underlie altered vibration-sensitivity.
 ...
PMID:Modulated vibration-sensitivity of lamprey Mauthner neurones. 358 44

Mechanisms underlying the potentiation of contractions after periods of high frequency stimulation (post-stimulation potentiation; PSP) and periods of rest (rest potentiation; RP) were investigated in isolated rat atria. Transmembrane action potentials were not changed during PSP and RP and were superimposable upon the pre-test action potentials. However, the 45Ca content of atrial strips was significantly increased during PSP, which indicates a net gain in intracellular Ca. 45Ca content was not changed during RP. PSP and RP were increased in magnitude in atria pre-treated with gallopamil (2.5 mumol/l). This effect was due to a greater depression by gallopamil of the pre-test contractions than the potentiated post-test contractions. In contrast, PSP was abolished in atria exposed to 7.5 mmol/l [Ca]o and a transient depression of the post-test contractions was seen. RP was also abolished by high Ca medium, but contractions were not depressed after periods of rest. RP, but not PSP, was unmasked when gallopamil was added to high Ca medium to decrease the size of the basal contractions. Conversely, ryanodine (100 mmol/l) abolished RP but did not affect PSP. With ryanodine present, PSP was greatly increased when the extracellular Ca concentration was increased to 5 mmol/l, whereas RP remained abolished. These results suggest that PSP may reflect an increased transsarcolemmal influx of extracellular Ca, possibly mediated through Na-Ca exchange. In contrast, the mechanism suggested for RP is a transient increase in contractile Ca resulting from an intracellular redistribution of Ca to release sites in the sarcoplasmic reticulum.
 ...
PMID:Mechanisms of frequency-induced potentiation of contractions in isolated rat atria. 382 39


1 2 3 4 5 6 7 8 9 Next >>