Human sleep EEG following the 5-HT1A antagonist pindolol: possible disinhibition of raphe neuron activity

The sleep electroencephalogram (EEG) was used to assay central effects of pindolol (10 and 30 mg p.o.), a mixed β_1/2-adrenoceptor/5-hydroxytryptamine (5-HT)_1A/1B receptor blocker, in humans. Compared to placebo, pindolol produced a dose-related suppression of rapid-eye-movement (REM) sleep, including a prolongation of REM latency, and a decrease of REM time and REM density. At the higher dose, it also reduced EEG spectral power during non-REM sleep in portions of the δ, θ, and α frequencies (1.125–5.125 Hz, 7.125–9.625 Hz). By contrast, betaxolol (20 mg p.o.), a selective β₁-antagonist devoid of serotonergic affinity, affected neither REM sleep nor EEG power. REM sleep is, in part, under the inhibitory control of serotonergic neurons projecting from the dorsal raphe nucleus to pontine cholinergic/cholinoceptive cells. The EEG power spectrum induced by pindolol tended to be opposite to what has previously been reported for ipsapirone, a 5-HT_1A agonist. Therefore, the present data, tentatively, are consistent with the contention that pindolol inhibits, possibly selectively, somatodendritic 5-HT_1A autoreceptors in humans and may antagonize self-inhibition of midbrain raphe nuclei 5-HT neurons.     

Long-term intraduodenal infusion of a water based levodopa-carbidopa dispersion in very advanced Parkinson's disease

Objective – To evaluate the effects of continuous duodenal infusion of levodopa over time on the disabling fluctuations in motor performance in advanced parkinsonian patients. It has earlier been demonstrated that these fluctuations can be reduced by keeping the plasma concentration of levodopa constant. Material and methods – In view of the low water solubility of levodopa a stable dispersion of the drug was developed and used for continuous intraduodenal infusion in patients with advanced Parkinson's disease. Nine patients were evaluated with respect to an optimal oral treatment, during nasoduodenal infusion by a portable pump and then followed for 6 months to 2½ years when treated via transabdominal infusion. Upon each test occasion, over 2 non-consecutive days, objective movement analysis by means of an opto-electronic system was applied every 15-20 min and video recordings performed twice every h. On several test occasions plasma levodopa concentrations were analysed every 15 min. Results – The patients showed improvement and decreased variance of their motor function. In the 2 patients followed over a period of 2½ years levodopa plasma concentration showed reduced fluctuations on infusion and the levodopa consumption as well as mean levodopa plasma concentration decreased. Conclusion – Continuous duodenal infusion of levodopa is an alternative treatment strategy for patients with advanced Parkinson's disease when conventional therapy has failed.     

Crossed and uncrossed central effects of muscle spindle afferents from the lateral pterygoid muscle of the guinea pig

Physiological evidence is presented for the presence of stretch reflexes in the lateral pterygoid (Pt) muscle of the guinea pig. The central reflex effects of excitation of Pt stretch reflex afferents were also investigated. Passive lateral jaw displacement, which resulted in stretch of the Pt muscle on the side of jaw movement and stretch of the zygomatico-mandibularis (Z) muscle on the side contralateral to the movement, evoked increased EMG activity in these muscles. Stimulation of the trigeminal mesencephalic nucleus (mes V) evoked monosynaptic reflexes in both the Pt and Z nerves. Tonic stretch of the Pt muscle facilitated the monosynaptic reflex in the Pt nerve evoked by stimulation of mes V. Tonic vibration of the Pt muscle facilitated the mes V evoked monosynaptic reflex in the nerves to the ipsilateral Pt and contralateral Z muscles. Conversely, tonic vibration of the Z muscle facilitated the monosynaptic reflex evolved by mes V stimulation in the contralateral Pt and ipsilateral Z nerve. The results support the view that muscle spindles exist in the Pt and Z muscles and that there is a monosynaptic stretch reflex for both the Pt and Z muscles with cell bodies located in the mes V nucleus. It was also shown that the ipsilateral Pt muscle and the contralateral Z muscle act as synergists in the production of lateral jaw movements and that the organization of the stretch reflexes originating from the Pt and Z muscles support their synergistic action.     

Functional localization in the three floccular zones related to eye movement control in the cat

Anatomically, the cat's cerebellar flocculus can be divided into 3 zones on the basis of differences in their efferent projection sites^13,14. The functional differences of these 3 zones in relation to eye movement control were investigated by observing the eye movements evoked by electric stimulation of each zone of the flocculus in ketamine-anesthetized cats. Stimulation of the flocculus elicited a slow eye movement. The direction of the slow eye movement was mapped. A downward eye movement was evoked by stimulation of the caudal zone. An ipsilateral horizontal eye movement was induced from the middle zone. An upward eye movement was elicited from the rostral zone. When prolonged stimulation was applied to the flocculus, the slow eye movement was followed by nystagmus in the opposite direction. This nystagmus persisted for many seconds after cessation of stimulation (afternystagmus). Nystagmus and afternystagmus could not be elicited in deeply anesthetized cats. Possibilities as to how the stimulation leads to various eye movements are discussed.     

Examination of geniculate ganglion cells contributing sensory fibers to the rat facial ‘motor’ nerve

Using a method to visualize HRP- containing cells in the geniculate ganglion (GG) in situ after decalcifying surrounding bone, we found that about 30% of the total (about 1000) GG cells contributed sensory fibers to the posterior auricular branch of the facial motor nerve. These cells are relatively large for GG cells in general. The remaining facial motor nerve branches, including those involved in vibrissal movement, contained few sensory afferent fibers originating from GG cells.     

Differentiation of the neural pathways mediating cortically induced and dopaminergic activation of the central pattern generator (CPG) for rhythmical jaw movements in the anesthetized guinea pig

The central pattern generator (CPG) for rhythmical jaw movements (RJMs) was activated, in the anesthetized guinea pig, by systemic injection of a specific dopamine agonist, apomorphine (APO). It was shown that APO induced RJMs required an intact superior colliculus, and were blocked by low doses (0.05-1.0 mg/kg) of haloperidol (HAL), a dopamine antagonist. This is in contrast to the neural pathways mediating RJMs evoked by repetitive electrical stimulation of the masticatory cortex which remained effective following both lesions of the superior colliculus and administration of HAL. These results suggest that there are at least two anatomically separate and pharmacologically distinct command centers for activation of the CPG for RJMs in the guinea pig.     

Perceptual and motor effects elicited by a moving visual stimulus below the forearm: an example of segmentary vection

It has been shown in man that movement of a visual stimulus under the forearm may induce illusory sensations of movement (segmentary vection) and motor activity in the same direction, such that, for example, a sensation of elbow flexion is accompanied by EMG activity in biceps brachialis. The characteristics of these two types of activity, perceptual and motor, are analyzed and compared with analogous phenomena described for the whole body. These comparisons bring out two essential features: the effectiveness of stimuli of small surface area applied to central regions of the retina, and the non-compensatory character of the motor phenomena. The results are discussed with respect to the participation of vision in the control and regulation of limb movements.     

Activists, gender and the community health movement

New social movements, including the self-help or community healthmovement, have developed in the context of the increasing difficultiesof the old Welfare State. This process has been politicallyfostered by left and right by a rhetoric of community self-helpas a means of reform. A central feature of these new movementsis that they draw on sophisticated approaches to change, flexiblyworking within, beside, or in opposition to the existing healthsystem. Their philosophy of empowerment has fostered flat organizationalforms, a commitment to health for all, and a distinctive approachto knowledge. This approach seeks to combine the rationalityof science with the rationality of caring. The paper pointsout that caring for health is largely women's work and thatgender blindness on the part of those wishing to promote healthfor all is theoretically negligent and practically counterproductive.Lastly through a discussion of US and UK approaches it is suggestedthat the political and cultural framework, within which suchgroups and movements are contextualized, must be taken intoaccount if we are to understand and support their potentialfor bringing about positive change.     

Kinetic activity of spermatozoa from fertile subjects and asthenozoospermic infertile patients

Summary. The motility characteristics of spermatozoa from asthenozoospermic semen were investigated and compared to the same parameters in fertile semen. The motility characteristics assessed by the CellSoft semen analyser (CRYO Resources Ltd, NY) were the following: curvilinear velocity (VCL), straight line velocity (VSL), amplitude of lateral head displacement (ALH), linearity (%LIN), and beat cross frequency (BCF).
Analysis of the data indicated a decreased kinetic activity in the spermatozoa from the astheno-zoospermic group which is expressed as a highly significant decrease ( P < 0.002) in the VCL and VSL compared to velocities from normospermic samples. Moreover, percentage linearity and ALH were also statistically lower ( P <0.05) in this group. However, no difference was evidenced for the BCF.     

Relative hand skill predicts academic ability: global deficits at the point of hemispheric indecision

Population variation in handedness (a correlate of cerebral dominance for language) is in part genetic and, it has been suggested, its persistence represents a balanced polymorphism with respect to cognitive ability. This hypothesis was tested in a sample of 12,770 individuals in a UK national cohort (the National Child Development Study) by assessing relative hand skill (in a square checking task) as a predictor of verbal, non-verbal, and mathematical ability and reading comprehension at the age of 11 years. Whereas some modest decrements were present in extreme right handers the most substantial deficits in ability were seen close to the point of equal hand skill (hemispheric indecision). For verbal ability females performed better than males, but the relationship to relative hand skill was closely similar for the two sexes; for reading comprehension males close to the point of equal hand skill showed greater impairments than females. Analysed by writing hand the relationship of ability to hand skill appeared symmetrical about the point of hemispheric indecision. The variation associated with degrees of dominance may reflect the operation of continuing selection on the gene (postulated to be X–Y linked) by which language evolved and speciation occurred.