Motor responses of the facial muscles to local stimulation of the motor cortex and facial nerve nucleus in the white mouse

The character of motor responses of the facial muscles evoked by stimulation of various regions of the frontal neocortex and of the nucleus of the facial nerve was studied in outbred mice. Motor responses of the vibrissae, of the upper lip and the jaw to monopolar microstimulation in the frontal cortical areas in 55 per cent of the cases had the latencies from 5 to 15 ms. The latencies of the responses to the facial nucleus stimulation ranged from 3 to 12 ms with maximal expressed interval of 4-6 ms. Excitation conduction velocities of the facial nerve estimated on the basis of latencies measurements, were from 1.5 to 12 m/s.     

The use of myoelectric feedback in teaching facial expression to the blind

Five blind subjects were provided with an auditory mirror of their facial activity by transducing myoelectric signals from facial muscles into sound. Expressions of happiness, surprise, and anger were defined primarily by involvement of thezygomaticus, thefrontalis, and thecorrugator, respectively. These muscles were connected through separate voltage-controlled oscillators to separate loudspeakers, such that each muscle activated a different speaker. Motion pictures taken before and after training were assembled in random order and were shown to preselected judges who attempted to identify the expressions. The judges were correct significantly more often on the posttraining expressions. Appropriateness and adequacy of expressions, as rated by the judges, also improved significantly as a result of training.     

The use of X-ray microanalysis to demonstrate the uptake of the molluscicide copper sulphate by slug eggs

Summary Copper has been localized in copper sulphate treated eggs of the slug Agriolimax reticulatus (Mü). This has been accomplished using a freeze-fracture technique, the freeze-dried halves of the fractured eggs being analysed in the scanning electron microscope, using both energy dispersive and wavelength dispersive X-ray microanalysis systems. The distribution of copper obtained using these methods has been compared with that achieved using a standard histochemical technique. Both techniques revealed that the copper is initially retained in the perivitelline membranes. The application of X-ray microanalysis to such studies is discussed.This research was supported by the Agricultural Research Council (G.B.), Grant No. AG 72/13     

Ipsilateral motor responses of the facial muscles to intracortical microstimulation in the white mouse

Motor responses (MRs) of facial muscles to intracortical microstimulation (ICMS) of lightly anaesthetized outbred white mice were observed visually and recorded by means of photodiodes. ICMS rostral to bregma, within cortical band along sagittal suture (area 6) evoked mostly ipsilateral MRs of vibrissae and upper lip, more often from the left hemisphere. MRs of the lower jaw, tongue and larynx were induced by ICMS in symmetrical zones of both hemispheres. The lowest thresholds of ICMS, 2-20 mcA, were revealed at the depth from 0.8-1.1 mm up to 1.3-1.7 mm, i. e. in layers III and V. Short-latency (from 10 to 25 ms) MRs of the vibrissae, lip and jaw were evoked by high-frequency volleys of 2 to 5 pulses. The participation of some oligosynaptic components in cortico-facial descending projections in the white mouse is supposed.     

Recognition of emotions by facial and verbal samples in healthy humans and patients with local brain pathology

The efficiency of emotion recognition by verbal and facial samples was tested in 81 persons (25 healthy subjects and 56 patients with focal pathology of premotor and temporal areas of brain hemispheres). The involvement of some cortical structures in the recognition of the basic emotional states (joy, anger, grief, and fear) and the neutral state was compared. It was shown that the damage to both right and left hemispheres impaired the recognition of emotional states by not only facial but also verbal samples. Damage to the right premotor area and to the left temporal area impaired the efficiency of the emotion recognition by both kinds of samples to the highest degree.     

Long-term comparison of a newly designed gold implant with the conventional implant in facial nerve paralysis.

Patients with complete facial nerve palsy are at risk for eye complications resulting from exposure of the cornea and loss of the blinking reflex. Failure of protection predisposes the patient to exposure keratitis, corneal abrasion and, in rare cases, blindness. The mainstays of non-surgical therapy are cumbersome, obscure vision, and are mostly helpful in patients with acute facial paralysis in whom recovery of orbicularis oculi function is expected. Methods of lid-loading using metal implants and gold eyelid weights have been reported in the literature. Between October of 1988 and March of 1995, 32 patients with lagophthalmos due to facial nerve palsy underwent a total of 34 procedures for the insertion of a gold eyelid weight. Each patient had a gold weight inserted into a small pocket between the orbicularis oculi and the tarsal plate of the upper eyelid. The gold implant is curved to fit the curvature of the eye and contains holes for fixation to the tarsus with sutures. Ingrowth of fibrous tissue through the holes may also help fix the weight in position. Between 1988 and 1991, 10 patients received 10 commercially available rectangular gold implants with 2 holes; these implants resulted in adverse effects, such as infection and exposure in up to 30 percent of the cases. Because of the high complication rate with the rectangular gold implant, the authors began using a new, elliptical gold implant with 3 holes, which is longer, thinner, wider in the center, and narrower in the peripheral portion. This new elliptical implant was used on 22 patients (24 implants) from December of 1991 through March of 1995. The mean follow-up time for the 32 patients in the study was 41.3 months (range, 6 to 63 months), 49.8 months for patients with rectangular implants and 32.8 months for patients with elliptical implants. The elliptical gold implant resulted in dynamic closure of the eyelid and in excellent protection and cosmesis. Lagophthalmos and exposure keratitis resolved, visual acuity significantly improved without complications, and most patients could dispense with eyedrops and salves. A lower eyelid supporting procedure (conchal cartilage graft) should be performed simultaneously in patients with lagophthalmos of a moderate or severe degree to achieve complete closure of the eyelid. Use of a tall pillow decreased the incidence of eyelid opening during sleep. Double eyelid fold operations'were performed on the contralateral eyelid after 6 months, resulting in a symmetrical and beautiful eyelid.