The Drosophila motor system starts to assemble during embryonic development. It is composed of 30 muscles per abdominal hemisegment and 36 motor neurons assembling into nerve branches to exit the CNS, navigate within the muscle field and finally establish specific connections with their target muscles. Several families of guidance molecules that play a role controlling this process as well as t...

The motor cortico-basal ganglion loop is critical for motor planning, execution, and learning. Balanced excitation and inhibition in this loop is crucial for proper motor output. Excitatory neurons have been thought to be the only source of motor cortical input to the striatum. Here, we identify long-range projecting GABAergic neurons in the primary (M1) and secondary (M2) motor cortex that tar...

In this study organotypic adult spinal cord slices were used to investigate whether caspases could participate in the apoptosis of motor neurons. The thoracic region of spinal cord was sliced using a tissue chopper and cultured in a medium for 6h. Morphological and biochemical features of apoptosis were assessed by fluorescent staining and terminal deoxynucleotidyl nick end labeling (TUNEL) met...

Although feeding in Aplysia is mediated by a central pattern generator (CPG), the activity of this CPG is modified by afferent input. To determine how afferent activity produces the widespread changes in motor programs that are necessary if behavior is to be modified, we have studied two classes of feeding sensory neurons. We have shown that afferent-induced changes in activity are widespread b...

1. Defensive inking behavior and gill withdrawal in ApIysia offer simple test systems in which the cellular and biophysial determinants of elementary behavioral acts can be examined. Since a good deal is known regarding both the behaviors and their underlying neural circuits, it is possible to compare directly these two defensive reflexes at the cellular level. 2. Both the ink and gill motor ne...

Apoptosis has been implicated in many neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS). We previously demonstrated a role for G1 to S phase cell cycle regulators in ALS with increased levels of hyperphosphorylated retinoblastoma (ppRb) and E2F-1 in ALS spinal cord motor neurons. In this study we examined the levels of the cell cycle checkpoint tumor suppressor protein p...

Coordination between different motor centers is essential for the orderly production of all complex behaviors, in both vertebrates and invertebrates. The current study revealed that rhythmic activities of two feeding structures of the pteropod mollusk Clione limacina, radula and hooks, which are used to extract the prey from its shell, are highly coordinated in a phase-dependent manner. Hook pr...