Rino Panu

Striated Perineal Muscles: Location of Autonomic, Sensory, and Somatic Neurons Projecting to the Male Pig Bulbospongiosus Muscle

The location, number, and size of the neurons innervating the bulbospongiosus muscle (BSM) were studied in male pigs, by means of Fast Blue (FB) retrograde transport. After injection of FB into the left BSM, labeled neurons were found bilaterally in the L2‐S4 sympathetic trunk ganglia (STGs), in the caudal mesenteric ganglia (CMGs), in the microganglia of the pelvic plexus (PGs), in a dorsolateral area with respect to the central canal of S1‐S3 segments of the spinal cord (SC) and in the S1‐S4 ipsilateral and S2‐S3 contralateral spinal ganglia (SGs). The mean number of labeled FB cells was 3,122 ± 1,968 in STGs, 979 ± 667 in CMGs, 108 ± 104 in PGs, 89 ± 39 in SC and 77 ± 23 in SGs. The area of the multipolar neurons was 852 ± 22 μm2 in the STGs, 878 ± 23 μm2 in the CMGs and 922 ± 31 μm2 in the PGs. The multipolar SC neurons had an area of 1,057 ± 38 μm2, while pseudounipolar SG cells had dimensions of 2,281 ± 129 μm2. Our research enables us to highlight two peculiarities regarding the innervation of the boar BSM: the very high number of labeled autonomic neurons and the particular localization of the motor somatic nucleus. Anat Rec, 2009.

Proprioceptive innervation of the external cremaster muscle of some domestic mammals

The proprioceptive innervation of the external cremaster muscle of some domestic animals was studied. Muscle spindles and tendon organs with their well-known features were found, but this finding was uncommon and unexpected in the investigated animals. For this reason, we believe that there is no relationship between the presence of these proprioceptors and the cremasteric reflex.

Striated Perineal Muscles: Location of Somatic and Autonomic Neurons Projecting to the Male Pig Ischiocavernous Muscle. Neurochemical Features of the Sympathetic Subset: NEURONS PROJECTING TO ISCHIOCAVERNOUS MUSCLE

The location, number and size of the central and peripheral neurons innervating the ischiocavernous muscle (ICM) were studied in male pigs by means of Fast Blue (FB) retrograde neuronal tracing. Moreover the immunohistochemical properties of the sympathetic ganglia were investigated combining the double immunolabeling method. After injection of FB into the left ICM, a mean number of 245.3 ± 134.9 labeled neurons were found in the ipsilateral ventral horn of the S1–S3 segments of the spinal cord (SC), 129.7 ± 45.5 in the L6‐S3 ipsilateral and S2–S3 contralateral spinal ganglia (SGs), 2279.3 ± 622.1 in the ipsilateral L2‐S2 and contralateral L5‐S2 sympathetic trunk ganglia (STGs), 541.7 ± 158 in the bilateral caudal mesenteric ganglia (CMGs), and 78.3 ± 35.8 in the microganglia of the pelvic plexus (PGs). The mean area of the ICM projecting neurons was 1217 ± 69.7 μm2 in the SC, 2737.5 ± 176.5 μm2 in the SGs, 982.8 ± 36.8 μm2 in the STGs, 865.9 ± 39.14 μm2 in the CMGs and 426.2 ± 24.72 μm2 in the PGs. The FB positive neurons of autonomic ganglia contained Dopamine β hydroxylase, vesicular acetylcholine transporter, neuronal nitric oxyde sinthase, calcitonine gene related peptide, leu‐enkephaline, neuropeptide Y, substance P, vasoactive intestinal polypeptide, and somatostatine often colocalized with tyrosine hydroxylase. The particular localization of the motor somatic nucleus, the abundant autonomic innervation and the qualitatively different content of ICM projecting sympathetic neurons suggest a complex regulation of this striated muscle involved in involuntary functions, such as the erection, ejaculation, micturition and defecation. Anat Rec, 301:837–848, 2018.

Double labelling immunohistochemistry on the sympathetic trunk ganglia neurons projecting to the extrinsic penile smooth musculature of the pig: an experimental study on the retractor penis muscle

Retrograde neuronal tracing and double labelling immunofluorescence methods were used to define the neurochemical content of sympathetic trunk ganglia neurons projecting to the pig retractor penis muscle, which was taken as an experimental model of the male genital smooth musculature. After the injection of Fast Blue into the bulbo-penile portion of the retractor penis muscle, the eventual co-existence of the catecholaminergic marker tyrosine hydroxylase with calcitonine gene related peptide, leu-enkephalin, neuropeptide Y, neuronal nitric oxide synthase, substance P, vasoactive intestinal polypeptide or vesicular acetylcholine transporter was studied in the ipsilateral S1 sympathetic trunk ganglia, which resulted to contain the greatest number of autonomic retractor penis muscle projecting cells. The observation of Fast Blue positive neurons under the fluorescent microscope allowed the identification of different subpopulations of catecholaminergic and non-catecholaminergic retractor penis muscle-projecting neurons. The majority of catecholaminergic cells contained tyrosine hydroxylase alone, while the remaining part showed co-localization of tyrosine hydroxylase with all the other tested markers. These last neurons were immunoreactive, in decreasing percentages, for neuropeptide Y, leu-enkephalin, neuronal nitric oxide synthase, substance P, calcitonine gene related peptide, vasoactive intestinal polypeptide and vesicular acetylcholine transporter. The majority of non-catecholaminergic neurons were immunonegative for all the tested markers. The remaining non-catecholaminergic cells contained, in decreasing percentages, neuropeptide Y, neuronal nitric oxide synthase, leu-enkephalin, vasoactive intestinal polypeptide, vesicular acetylcholine transporter, substance P and calcitonine gene related peptide. Our findings documented the complexity of the neurochemical interactions that regulate both the motor functions of RPM and the blood flow through the muscle.

Immunohistochemical characteristics of the nerve fibres of sow retractor clitoridis muscle

The occurrence of several biologically active neuropeptides (calcitonine gene-related peptide, leu-enkephaline, neuropeptide Y, substance P, and vasoactive intestinal peptide) or nitric oxide-synthesizing enzymes (neuronal nitric oxide synthase), tyrosine hydroxylase, vesicular acetylcholine transporter, and their co-localization with tyrosine hydroxylase were investigated by immunohistochemistry in the retractor clitoridis muscle of slaughtered sows. Single immunolabelling revealed that tyrosine hydroxylase and neuropeptide Y immunoreactive nerve fibres were the most numerous, followed by the neuronal nitric oxide synthase and calcitonine gene-related peptide immunoreactive ones, the vasoactive intestinal peptide, substance P and leu-enkephaline immunoreactive nerve fibres were few and vesicular acetylcholine transporter immunoreactivity were observed only in single fibres. Double immunolabelling revealed the only co-localization of tyrosyne hydroxylase with neuropeptide Y. The most reliable labelling of nerve fibres of the retractor clitoridis muscle was observed around blood vessels, followed by non-vascular smooth muscles. The present data indicate that the sow retractor clitoridis muscle receives nerve fibres that exhibit different chemical codes and, likely, differences in their chemical coding depend on the target-structure.

The Motor and Proprioceptive Innervation of the Retractor Bulbi Muscle of the Lamb

The motor and proprioceptive innervation of the retractor bulbi muscle of the lamb has been studied. The motor innovation of the muscles supplied only by the abducens never. The proprioceptive nervous fibers coming from the muscle spindles of this extraocular muscle enter the brain stem through the ophthalmic branch of the trigeminal nerve and have their perikarya in the semilunar ganglion.