Whether afferents exert their morphogenetic influence on spindles through release of trophic factors at intrafusal fiber junctions or via participation in proprioceptive pathways which modulate the motor activity to muscles was investigated by…
The effects of a deletion for the brain derived neurotrophic factor (BDNF) allele (+/- BDNF) upon age-related changes in nigrostriatal dopaminergic (NSDA) function were assessed. Behavioral (beam crossing and spontaneous activity) and neurochemical…
The pattern of regional expression of a slowtonic myosin heavy chain (MHC) isoform was studied in developing rat soleus intrafusal muscle fibers. Binding of the slow-tonic antibody (ATO) began at the equator of prenatal intrafusal fibers where…
The influence of brain-derived neurotrophic factor (BDNF) upon the nigrostriatal dopaminergic system was evaluated in weanling and adult mice carrying a targeted inactivated BDNF gene. Regional specificity of this BDNF mutation was assessed by…
Muscle fibers develop sequentially from several generations of myotubes that express specific isoforms of myosin heavy chain (MHC). We observed that the chicken-derived monoclonal antibody (mAb) S46 binds to myotubes of the fetal rat hindlimb in a…
The response of developing muscle spindles to denervation was studied by sectioning the nerve to the medial gastrocnemius muscle of rats at birth. The denervated spindles were examined daily throughout the first postnatal week for changes in…
Deletion of a single copy of the BDNF gene has been shown to affect the nigrostriatal dopaminergic system of young adult BDNF mice. In the present report we evaluated various indices of nigrostriatal dopaminergic function between
Whether any fibers in rat hindlimb muscles express alpha-cardiac myosin heavy chain (MHC) is uncertain. Expression of alpha-cardiac MHC mRNA and the polypeptide for which it codes were examined in control and denervated rat muscle spindles using in…
Myosin heavy chain (MHC) expression by intrafusal fibers was studied by immunocytochemistry to determine how closely it parallels MHC expression by extrafusal fibers in the soleus and tibialis anterior muscles of the rat. Among the MHC isoforms…
Whether muscle spindles can form in muscles innervated only by afferents was investigated by removing the lumbosacral segment of the spinal cord immediately after crushing the nerve to the medial gastrocnemius (MG) muscle in newborn rats, and…
Crushing the nerve to the medial gastrocnemius muscle in newborn rats and administering nerve growth factor afterwards results in a reinnervated muscle containing supernumerary muscle spindles. The structure and innervation of 88 spindles in the…
Whether two copies of the neurotrophin-3 (NT3) gene are necessary for proper development of cardiac sympathetic innervation was investigated in mice carrying a targeted inactivation of the NT3 gene. Heterozygous (+/-) and null (-/-) mutant mice had…
Rat muscle spindles contain one nuclear bag2, one nuclear bag1, and two nuclear chain fibers. The three different types of intrafusal fiber in spindles may be a reflection of concomitant changes in proportions of slow primary, slow/fast secondary,…
Features of the nerve supply and the encapsulated fibers of muscle spindles were assessed in grafted and normal extensor digitorum longus (EDL) muscles of rats by analysis of serial 10-microns frozen transverse sections stained for enzymes which…
Depletion of dopamine (DA) reduces D, receptor number, but D-3 receptor expression is also regulated by brain-derived neurotrophic factor (BDNF). We took advantage of transgenic heterozygous BDNF mutant mice (+/-) to determine if reduced BDNF and…
The incidence of coated vesicles under sarcolemmal surfaces of equatorial, juxtaequatorial and polar regions in developing and adult spindles of the rat soleus muscle was examined by quantitative morphometry of transverse ultrathin sections. Coated…
Two factors, the ETS transcription factor ER81 and skeletal muscle-derived neurotrophin-3 (NT3), are essential for the formation of muscle spindles and the function of spindle afferent-motoneuron synapses in the spinal cord. Spindles either…
Expression of myosin heavy chain (MHC) isoforms was studied in rat soleus (SOL) and extensor digitorum longus (EDL) muscles which regenerated in the presence or absence of innervation. Frozen sections of two 5 day denervated SOL and EDL grafts, two…
Expression of myosin heavy chain (MHC) isoforms was studied in rat soleus (SOL) and extensor digitorum longus (EDL) muscles which regenerated in the presence or absence of innervation. Frozen sections of two 5 day denervated SOL and EDL grafts, two…
