Diabetes mellitus and brain atrophy: a computed tomography study in an elderly population.

Previous studies have suggested that noninsulin dependent diabetes mellitus (NIDDM) could lead to learning and memory deficits. We studied cognitive performance and computed tomography (CT) findings of the brain in elderly subjects with drug treated NIDDM (n = 12), with diet treated NIDDM (n = 13), and in nondiabetic individuals (ND, n = 59). The cognitive performance (orientation and up-to-date knowledge, praxic functions, understanding of speech, expressive speech, memory, general reasoning) did not differ between the groups.

Pre- and postoperative auditory event-related potentials in temporal lobe epilepsy.

We studied auditory event-related potentials (ERPs) in 11 surgically treated patients with intractable temporal lobe epilepsy (TLE) pre- and postoperatively. ERPs through sphenoidal electrodes (Sp1-T3, Sp2-T4) provided clinically relevant and correctly lateralizing electrophysiologic evidence of temporal lobe dysfunction in 9 of 11 patients, confirmed by EEGs, electrocorticograms, neuroradiologic, and neuropsychological results, and clinical follow-up. Lateralizing asymmetries were noted in P300 amplitude, but latencies were prolonged bilaterally.

Continuous alpha 2-adrenoceptor blockade by atipamezole decreases neocortical high-voltage spindle activity in rats.

The present study investigates the effects of a subchronic continuous infusion of atipamezole, a potent and selective alpha 2-adrenoceptor antagonist, on neocortical high-voltage spindle (HVS) activity in rats. Six days' subcutaneous infusion of atipamezole (0.125 mg/kg per h) with osmotic minipumps decreased HVS activity significantly.

Attenuation by the benzodiazepine receptor antagonist, ZK 93 426, of the deficit in spatial navigation induced by nucleus basalis lesions.

The effects of the benzodiazepine receptor antagonist, beta-carboline ZK 93,426 treatment were studied both in NB-lesioned (ibotenic acid) and in unoperated Kuo-Wistar rats in a water maze task. The ZK 93,426 administered in the doses of 1 and 5 mg/kg, 30 min prior to the testing in a water maze apparatus, attenuated the NB lesion-induced spatial navigation deficit, although it had no effect on the performance of unoperated rats. The results suggest functional interactions between GABAergic system and ibotenic acid-induced lesion of the basal forebrain in rats.

Effects of an inhibitor of GABA-aminotransferase (gamma-vinyl-GABA) on the spatial navigation deficit induced by muscarinic blockade.

The present study investigated whether stimulation of the GABAergic system affects spatial navigation [water-maze (WM)] deficit induced by muscarinic blockade (scopolamine). The effects of various doses of gamma-vinyl-GABA (GVG) (50, 150, and 300 mg/kg) and scopolamine (0.4 and 0.

Gamma-vinyl GABA (vigabatrin) in epilepsy: clinical, neurochemical, and neurophysiologic monitoring in epileptic patients.

We report long-term clinical, neurochemical, and electrophysiologic data of gamma-vinyl GABA (GVG, vigabatrin) in three groups of patients. GVG was started as add-on therapy for 75 patients with refractory complex partial seizures (group A) and for 36 mentally handicapped patients with severe epilepsy (group B). The third group (C) consisted of 20 patients with carbamazepine (CBZ) monotherapy, in half of whom GVG monotherapy was substituted.

Effects of atipamezole, an alpha 2-adrenoceptor antagonist, on the performance of rats in a five-choice serial reaction time task.

The present study investigates whether pharmacological activation of the noradrenergic system improves attention. The effects of atipamezole, a potent alpha 2-adrenoceptor antagonist, on the performance of adult male rats in the five-choice serial reaction time task were studied. Before drug testings, food-deprived rats were trained to detect and respond to brief flashes of light presented randomly by the computer in one of five spatially diverse locations until a stable level of performance had been reached (about 3 months).

Slowing of electroencephalogram and choline acetyltransferase activity in post mortem frontal cortex in definite Alzheimer's disease.

Twenty-five (96%) of 26 patients with histologically verified moderate to severe Alzheimer's disease had abnormal electroencephalograms. The patients with the slowest (5-6 Hz) dominant occipital rhythms had significantly lower choline acetyltransferase activity in the post mortem frontal cortex than the patients with highest rhythm (8-9 Hz) (analysis of covariance adjusted for the neuropsychological test score). Concentrations of dopamine, noradrenaline or serotonin in the frontal cortex did not differ in the patient groups with the slowest and highest rhythms.

Aging and spectral analysis of EEG in normal subjects: a link to memory and CSF AChE.

We studied the effect of aging on EEG spectra recorded from T5-O1 (T6-O2) derivation. The aging series composed of 52 normal individuals aged 20 to 91 years. Seventy-nine per cent of visual and 81% of quantitative EEGs were considered normal.

Effects of combined methysergide and mecamylamine/scopolamine treatment on spatial navigation.

In the present study, we investigated the effects of a 5-HT2 receptor antagonist, methysergide (2.5, 7.5 and 20 mg/kg), on spatial learning in saline, mecamylamine (10 mg/kg) and scopolamine (0.

Population-based dementia screening program in Kuopio: the effect of education, age, and sex on brief neuropsychological tests.

A neuropsychological screening battery including the Mini-Mental State Examination and four other brief cognitive tests (Russell's Adaptation of the Visual Reproduction Test, Trail Making Test, Verbal Fluency Tests on letters and category, and the Buschke Selective Reminding Test) was administered to a randomly selected population sample of 403 subjects aged 68 to 77 years to evaluate the effect of education, age, and sex on test scores. The difference in neuropsychological screening tests between various education groups (3 years or less, 4 to 6 years, 7 years or more) was statistically highly significant, even after the adjustment for the effect of age. The subscores and total scores were lowest in the minimal education group on every neuropsychological test.

Effects of noradrenergic DSP4 lesion on the effectiveness of pilocarpine in reversing scopolamine-induced amnesia.

We studied the effectiveness of pilocarpine in reversing the scopolamine-induced water maze learning deficit (increase in escape latencies, decrease in spatial bias) in control and DSP4- (a noradrenergic neurotoxin) lesioned rats. The water maze acquisition deficit (escape latency, first spatial bias) induced by scopolamine 0.8 mg/kg was augmented by DSP4 treatment.

European stroke prevention study: effectiveness of antiplatelet therapy in diabetic patients in secondary prevention of stroke.

Background And Purpose: The European Stroke Prevention Study was a multicenter trial comparing the effect of a combination of 75 mg dipyridamole and 330 mg acetylsalicylic acid three times a day with the effect of a placebo in the prevention of stroke or death in 1,861 patients after one or more episodes of recent transient ischemic attack or cerebral infarction.

Methods: The present study represents a secondary analysis of the efficacy of study medication in diabetic (n = 216) and nondiabetic (n = 1,645) patients.

Results: The risk of end point events was greater in diabetic than in nondiabetic subjects.

Cognitive effects of oxcarbazepine and phenytoin monotherapy in newly diagnosed epilepsy: one year follow-up.

We evaluated the effect of initial oxcarbazepine (OXC) monotherapy on memory, attention and simple psychomotor speed in 14 patients; 15 patients with initial phenytoin (PHT) monotherapy served as reference patients. Neuropsychological assessments were performed before starting the treatment and after 6 and 12 months follow-up with steady-state drug treatment. Differential cognitive effects of OXC and PHT were not apparent in our study.

Fast cyclic voltammetry of oxidizable species; depth profile in the rat striatum with and without potassium stimulation of the median forebrain bundle.

Fast cyclic voltammetry was used to monitor the release of dopamine in the caudate nucleus following potassium stimulation of the median forebrain bundle and to determine the characteristics of the small basal oxidation current while dipping of an electrode with a large tip (0.3 mm) in the caudate nucleus. The oxidation current was shown to be greater just after the electrode reached the caudate area than at a time 15-20 s after its arrival.

Neurophysiological consequences of combined cholinergic and noradrenergic lesions.

The present study investigates the effects of an anti-cholinesterase, tetrahydroaminoacridine (THA), on combined nucleus basalis (NB, quisqualic acid) and dorsal noradrenergic bundle (DNB, 60HDA) lesion-induced high-voltage spindle (HVS) activity. THA at 3 mg/kg, but not at 1 mg/kg, decreased HVS activity in NB- and DNB-lesioned rats. HVS activity in NB- and DNB-lesioned rats treated with THA at 6 mg/kg was lower than in saline-treated controls.

Amygdala kindling increased fear-response, but did not impair spatial memory in rats.

The behavioral effects of amygdala kindling, a model of experimental epilepsy in rats, are reported. The animals were stimulated twice a day until stage 5 (generalized clonic) seizures were obtained three times. Two weeks later the performance of the amygdala-kindled and sham-operated rats was tested in the open-field test, on the elevated plus maze, elevated bridges, and in the Morris water maze.

JC virus infection and Alzheimer's disease: reappraisal of an in situ hybridization approach.

To assess the validity of the recently reported data on frequent occurrence of latent JC virus (JCV) infections in the brains of patients with Alzheimer's disease, we used in situ hybridization with biotinylated whole genomic JCV probes and the streptavidin-biotinylated alkaline phosphatase method to examine brain sections of such patients. We did not find any signs of JCV either in the brains of the patients with Alzheimer's disease or in those of nondemented, elderly control patients. Non-specific staining of corpora amylacea-like bodies, however, was invariably detected with in situ hybridization using JCV probes.

Effects of concurrent nicotinic antagonist and PCPA treatments on spatial and passive avoidance learning.

The present study investigates the effects of concurrent manipulations of nicotinic cholinergic receptors (mecamylamine 10 mg/kg, i.p.) and serotonin neurons (PCPA, 400 mg on each of 4 days) on spatial navigation (water maze, WM) and passive avoidance (PA) performance.

Slowing of the dominant occipital rhythm in electroencephalogram is associated with low concentration of noradrenaline in the thalamus in patients with Alzheimer's disease.

The thalamus is involved in the regulation of the neocortical rhythmicity reflected in EEG as the alpha rhythm. Recent evidence suggests that the thalamus is affected in Alzheimer's disease (AD). We studied the relationship between the dominant occipital rhythm of the lifetime EEG and the choline acetyltransferase activity (ChAT) and monoamine concentrations in the postmortem thalamus of 20 histologically verified AD patients.

Effects of tetrahydroaminoacridine on spatial navigation of nucleus-basalis- and frontal-cortex-lesioned rats.

The present study investigates the effects of tetrahydroaminoacridine (THA: 1 and 3 mg/kg) on water maze (WM) spatial learning performance of intact, nucleus-basalis- (NB) lesioned, frontal-cortex- (FR) lesioned, or NB + FR-lesioned rats. NB lesions did not impair WM learning and had no effect on the WM performance deficit in FR-lesioned rats. THA at 1 or 3 mg/kg did not improve WM spatial memory of intact, NB-, FR-, or NB + FR-lesioned rats.

Atipamezole, an alpha 2 antagonist, stabilizes age-related high-voltage spindle and passive avoidance defects.

The present study investigates the effects of an alpha 2 antagonist, atipamezole (Ati), on the high-voltage spindle (HVS; Ati at 0.1, 1.0, and 3.

The effects of dexmedetomidine, an alpha 2 agonist, on learning and memory, assessed using passive avoidance and water maze tasks in rats.

The effects of dexmedetomidine, a specific and potent alpha 2 agonist, on the performance of rats in passive avoidance and water maze tasks were studied. Pre-training administration of subanaesthetic dose (9.0 micrograms/kg) of dexmedetomidine impaired the retention of the passive avoidance task (assessed 24 hr after training) but it did not affect the training of this task.

DSP-4, a noradrenergic neurotoxin, produces more severe biochemical and functional deficits in aged than young rats.

The present study examines the effects of noradrenergic lesions (either DSP-4 i.p. or 6-hydroxydopamine (6-OHDA) into the dorsal noradrenergic bundle on biochemical (noradrenaline (NA), dopamine (DA), serotonin (5-HT) and choline acetyltransferase (ChAT) activity) and cortical EEG (quantitative EEG (qEEG) and high-voltage spindle (HVS)) activity in young and aged rats.