Biomedical subjects

A Kirzinger

Publications and source records attributed to A Kirzinger.

9 recordsLinked to original sources

PubMed1994

Role of extralaryngeal muscles in phonation of subhuman primates.

1. The electromyographic activity of eight external laryngeal and hyoid muscles was recorded during vocalization in the squirrel monkey (Saimiri sciureus). Calls of different types were elicited by electrical stimulation of the central grey of the midbrain in narcotized animals. 2. Peeping, a short, high-pitched call with minor frequency modulations, is associated with a marked activity in the cricothyroid, a moderate activity in the thyrohyoid, a weak activity in the sternohyoid and no activity in the sternothyroid, omohyoid, mylohyoid and anterior digastric muscles. 3. Chuck, a short, plosive call with a steep frequency descent over several kHz, is associated with a marked activity in the cricothyroid, a moderate activity in the thyrohyoid, sternothyroid and mylohyoid, a weak activity in the sternohyoid and omohyoid, and no or rare activity in the anterior digastric and inferior pharyngeal constrictor, respectively. 4. Cackling, a long and loud call consisting of alternating high- and low-pitched elements which follow each other repetitively in a 12-14 Hz rhythm, is associated with a similar muscular activity pattern as chuck except that the sternohyoid activity is relatively stronger. 5. Cawing, a short low-pitched call with a fundamental frequency of 200-700 Hz, shows a moderate activity in the sternothyroid, an occasional activity in the thyrohyoid and no activity in the cricothyroid, sternohyoid, omohyoid, anterior digastric and inferior pharyngeal constrictor.

Animals↗

PubMed1994

Motoneuronal location of external laryngeal and hyoid muscles involved in primate phonation.

In seven squirrel monkeys (Saimiri sciureus), horseradish-peroxidase injections were made into a number of extralaryngeal muscles shown to be involved in vocal control. Retrogradely labeled motoneurones were found in the case of the strap muscles from a position ventrolateral to the caudal hypoglossal nucleus down into the ventral horn of C2. The thyrohoid muscle was represented most rostrally, the sternothyroid most caudally; the sternohyoid took an intermediate position. There was partial overlap between sternothyroid and sternohyoid motoneurones. The thyrohyoid motoneurones were located not only rostrally but also laterally to the sternohyoid motoneurones. Omohyoid motoneurones overlapped with those of the sternohyoid and sternothyroid in the caudal medulla; in the cervical cord, they were located laterally to them. Inferior pharyngeal constrictor motoneurones were found in the nucl. retrofacialis and rostral nucl. ambiguus. Mylohyoid and anterior digastric motoneurones were restricted to the medialmost part of the trigeminal motor nucleus, with the mylohyoid being represented ventrally to the anterior digastric.

Animals↗

PubMed1991

Vocalization-correlated single-unit activity in the brain stem of the squirrel monkey.

The brain stems of 17 squirrel monkeys (Saimiri sciureus) were systematically explored for vocalization-related single-unit activity during calls electrically elicited from the periaqueductal grey. Of 12,280 cells tested, 1151 fired in relation to vocalization. Of these, 587 reacted to external acoustic stimuli and started firing after vocalization onset. As most of these cells were located in classical auditory relay structures, they probably represent auditory neurones reacting indirectly to self-produced vocalization due to auditory feedback. Seven cells reacted to acoustic stimuli but fired in advance of self-produced vocalization. These cells were located in the pericentral inferior colliculus, dorsal nucleus of the lateral lemniscus, dorsomedial to the ventral nucleus of the lateral lemniscus and immediately lateral to the central grey. They are probably engaged in tuning the auditory system to process self-generated sounds differently from external sounds. 261 neurones reacted to nonphonatory oral movements (chewing, swallowing) and started firing after vocalization onset. These neurones were widely distributed within the brain stem, with the highest density in the spinal trigeminal nucleus and medially adjacent reticular formation. The majority of these cells seem to react to proprioceptive and tactile stimuli generated by phonatory and nonphonatory oral activities. Some of them may exert motor control on muscles that come into play at later stages of phonation. 57 neurones reacted to nonphonatory oral movements but fired in advanced of vocalization onset. These neurones were located mainly in the trigeminal motor nucleus, nucl. ambiguous, reticular formation around these nuclei, parabrachial region and lateral vestibular nucleus. Their role in motor control seems to be related to specific muscles rather than specific functions. 100 of the vocalization-related cells showed a correlation with respiration. Expiration-related cells were found in and around the rostral nucl. ambiguous and in the reticular formation dorsal to the facial nucleus. Inspiration-related cells were located in the rostral and caudal nucl. ambiguous regions, ventrolateral solitary tract nucleus and the lateral reticular formation below the trigeminal motor nucleus. Most of these cells probably represent premotor neurones of respiratory muscles and laryngeal motoneurones of the cricothyroid and posterior cricoarytenoid muscles. Finally, a last group of cells was found that was unresponsive to chewing and swallowing movements, quiet breathing and acoustic stimuli, but changed activity during vocalization. 38 of them became active before vocalization and cricothyroid activity, and 101 afterward.(ABSTRACT TRUNCATED AT 400 WORDS)

Acoustic Stimulation↗

PubMed1990

Chemical brain stimulation as a means to circumvent electrical stimulation artefacts in single-unit recording studies of evoked vocalization.

This study describes a combined single-unit recording/chemical brain stimulation technique that proved to be helpful in cases in which the behavior pattern to be studied electrophysiologically is difficult to elicit repetitively by external stimuli, but is easily obtained by brain stimulation. The advantage of this technique over electrical elicitation of the behavior is the avoidance of periodic stimulation artefacts that make detailed analyses of pattern-correlated neuronal activity often impracticable. Out of a number of substances tested for chemical brain stimulation, kainic acid proved to be the most effective one. With a single injection of 50 ng (in 200 nl water) into the periaqueductal gray of the squirrel monkey up to 6480 vocalizations could be obtained over a period of 65 min. Up to 22 injections could be made at this dose before a site became unresponsive.

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PubMed1985

The effects of brainstem lesions on vocalization in the squirrel monkey.

The present study is an attempt to find out the brain areas involved in the motor coordination of species-specific vocalization. For this purpose, high-frequency coagulations were placed in a systematic manner throughout the brainstem and posterior diencephalon in altogether 43 squirrel monkeys (Saimiri sciureus). The effect of these lesions on different call types elicited by electrical brain stimulation was studied spectrographically. It was found that bilateral destruction of the ventrolateral, ventroposterior and intralaminar thalamus, periventricular and rostral periaqueductal gray, ventral tegmental area of Tsai, nucl. interpeduncularis, nucl. ruber, anterodorsolateral midbrain tegmentum, superior and inferior colliculi, pontine gray, cerebral peduncles, medial pontine reticular formation, raphe and vestibular nuclei did not affect the acoustic structure of the calls tested. On the other hand, lesions in the ventrolateral midbrain involving the substantia nigra and overlying reticular formation, in the midbrain tegmentum just below the inferior colliculus, in the lateral pons and almost the whole medulla (minimal lesion size: 2.5 mm3) changed vocalization significantly. It is suggested that the latter areas are more or less directly involved in the motor coordination of vocalization, while the first are not.

Animals↗

PubMed1985

The laryngeal sensory pathway and its role in phonation. A brain lesioning study in the squirrel monkey.

In 10 squirrel monkeys (Saimiri sciureus) uni- or bilateral lesions were placed in the nucl. solitarius, parabrachial nuclei, nucl. ventralis posterior medialis thalami or face area of primary sensory cortex. The effects of these lesions on vocalization were compared with those after transection of the internal branch of the superior laryngeal nerve. It was found that neither the cortical nor thalamic or parabrachial lesions changed the acoustic structure of vocalization. In contrast, destruction of the nucl. solitarius, like transection of the internal branch of the superior laryngeal nerve, affected vocalization severely. It is concluded that the production of species-specific vocalization depends upon a di- or, possibly, tri-synaptic laryngeal reflex control from tactile and proprioceptive laryngeal mechanoreceptors via nucl. solitarius and, possibly, lateral medullary reticular formation to nucl. ambiguus.

Animals↗

PubMed1985

Cerebellar lesion effects on vocalization of the squirrel monkey.

High-frequency coagulations were made in the cerebellar nuclei of 3 adult squirrel monkeys to test their role in the production of vocalization. Complete bilateral destruction of all 3 nuclei in one animal or destruction of their rostral or caudal halves in the other two had no effect on the acoustic structure of electrically elicited species-specific calls.

Animals↗

PubMed1982

Cortical lesion effects and vocalization in the squirrel monkey.

The effects of bilateral destruction of the cortical face area, anterior and posterior supplementary motor area and anterior cingular cortex on spontaneous vocalization were studied in 16 squirrel monkeys (Saimiri sciureus). Each type of lesion was made in two groups of two animals each. Both animals of a group received the same type of lesion at the same day. Each group was recorded for 10 sessions of one hour before operation and 10 sessions after operation. Pre- and post-operative vocalizations were compared in respect to total number and acoustic structure. It was found that none of the lesions affected acoustic structure as judged by a sonagraphic analysis. However, lesions in the anterior supplementary motor area (at the level of the callosal genu) reduced the total vocalization number significantly. This decrease was essentially due to a drastic reduction of the so-called isolation peep, a long-distance contact call. The results suggest: (i) that the cortical face area is only involved in the control of learnt vocal utterances (such as human speech and song) but not in the production of genetically preprogrammed utterances (such as monkey calls and human pain groans); (ii) that the anterior cingulate cortex is necessary for the volitional initiation of vocalization but not for the initiation of calls in an emotional situation; (iii) that the posterior supplementary motor area does not play any role in vocal behaviour of monkeys; and (iv) that the anterior supplementary motor area is involved in the production of vocalization which are not triggered directly by external events.

Animals↗

PubMed1982

The effects of deep-reaching lesions in the cortical face area on phonation. A combined case report and experimental monkey study.

The present study compares the phonatory ability of a patient with a deep-reaching left-sided lesion in the region of the cortical face area with that of two squirrel monkeys in which the patient's lesion has been reduplicated bilaterally. The lesion involved Broca's area, the inferior pre- and postcentral cortex, rolandic operculum, inferior parietal cortex insula, claustrum, parts of the putamen and white matter underlying the inferior frontoparietal and insular cortex. While the squirrel monkey did not show any phonatory deficits, the patient became aphonic for more than 10 weeks following the insult. After that period, phonation recovered steadily to a slightly breathy but monotonous voice with a somewhat reduced singing capacity. During the aphonic period, there was a bilateral complete paresis of the vocal folds. Both, patient and monkey, showed a paresis of the lower facial and tongue muscles which was accompanied by dysarthria and buccolingual apraxia in the patient and feeding difficulties in the monkey. The discrepancy between human aphonia and intact monkey phonation, on the one hand, and intact phonation and defective orofacial behaviour in the monkey, on the other, is explained by the anatomical fact that there is a direct cortical projection to the nucleus ambiguus in man but not in monkey, whereas the facial and hypoglossal nuclei receive direct cortical projections in man and monkey. The lack of direct cortical control of the laryngeal motoneurones in the monkey is paralleled by a lack of volitional control of fine vocal fold movements.

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