Identification of c-Fos immunoreactive brainstem neurons activated during fictive mastication in the rabbit.
In the present study we used the expression of the c-Fos-like protein as a "functional marker" to map populations of brainstem neurons involved in the generation of mastication. Experiments were conducted on urethane-anesthetized and paralyzed rabbits. In five animals (experimental group), rhythmical bouts of fictive masticatory-like motoneuron activity (cumulative duration 60-130 min) were induced by electrical stimulation of the left cortical "masticatory area" and recorded from the right digastric motoneuron pool. A control group of five animals (non-masticatory) were treated in the same way as the experimental animals with regard to surgical procedures, anesthesia, paralysis, and survival time. To detect the c-Fos-like protein, the animals were perfused, and the brainstems were cryosectioned and processed immunocytochemically. In the experimental group, the number of c-Fos-like immunoreactive neurons increased significantly in several brainstem areas. In rostral and lateral areas, increments occurred bilaterally in the borderzones surrounding the trigeminal motor nucleus (Regio h); the rostrodorsomedial half of the trigeminal main sensory nucleus; subnucleus oralis-gamma of the spinal trigeminal tract; nuclei reticularis parvocellularis pars alpha and nucleus reticularis pontis caudalis (RPc) pars alpha. Further caudally-enhanced labeling occurred bilaterally in nucleus reticularis parvocellularis and nucleus reticularis gigantocellularis (Rgc) including its pars-alpha. Our results provide a detailed anatomical record of neuronal populations that are correlated with the generation of the masticatory motor behavior.
Athanassiadis
T
T
Department of Integrative Medical Biology, Section for Physiology, Umeå University, 901 87, Umeå, Sweden.
Olsson
K A
KA
Kolta
A
A
Westberg
K-G
KG
D000758:Anesthesia; D000818:Animals; D001933:Brain Stem / Q000378:metabolism*; D003627:Data Interpretation, Statistical; D004525:Efferent Pathways / Q000166:cytology / Q000502:physiology; D004558:Electric Stimulation; D007150:Immunohistochemistry; D008297:Male; D008409:Mastication / Q000502:physiology*; D008410:Masticatory Muscles / Q000294:innervation / Q000502:physiology; D008839:Microelectrodes; D009044:Motor Cortex / Q000502:physiology; D009046:Motor Neurons / Q000502:physiology; D009474:Neurons / Q000378:metabolism*; D010243:Paralysis / Q000503:physiopathology; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D011817:Rabbits
D016760:Proto-Oncogene Proteins c-fos