... (whole-body and local shortening) to repeated mechanical nociceptive stimuli (needle pokes) in the medicinal leech, Hirudo verbana , and assess whether injury altered habituation to these nociceptive stimuli. While repeated needle pokes did reduce shortening in H. verbana , a second set of behavior...

...Daniel A. Wagenaar ABSTRACT The medicinal leech (genus Hirudo ) is a classic model animal in systems neuroscience. The leech has been central to many integrative studies that establish how properties of neurons and their interconnections give rise to the functioning of the animal at the behavioral...

... be thermodetectors in many animal phyla. In this study, we provide the first pharmacological evidence of a putative TRPA1-like channel in the medicinal leech. The leech's polymodal nociceptive neuron was activated by both peripheral and central application of the TRPA1 agonist AITC in a concentration-dependent...

...Sarah E. DuRant; William A. Hopkins; Andrew K. Davis; L. Michael Romero ABSTRACT Parasitic leeches and trypanosomes release chemical signals into their hosts to evade immuno-detection, but it is unknown whether these compounds manipulate host behavior or endocrine physiology. We determined whether...

... the presence of a putative TRPV-like receptor in the medicinal leech, building upon earlier studies in this lophotrochozoan invertebrate. The leech polymodal nociceptive neuron was activated by both peripheral and central application of the TRPV1-activator capsaicin in a concentration-dependent manner...

... determinants of behavior quite complex. We observed the behavioral responses of European leeches, Hirudo verbana , as we varied one external factor (surrounding water depth) with either another external factor (location of tactile stimulation along the body) or an internal factor (body distention following...

...John Jellies Medicinal leeches are aquatic predators that inhabit surface waters during daylight and also leave the water where they might be exposed to less screened light. Whereas the leech visual system has been shown to respond to visible light, leeches in the genus Hirudo do not appear...

...Cynthia M. Harley; Matthew Rossi; Javier Cienfuegos; Daniel Wagenaar SUMMARY The medicinal leech, Hirudo verbana , is an aquatic predator that utilizes water waves to locate its prey. However, to reach their prey, the leeches must move within the same water that they are using to sense prey...

...Daniel Kueh; John A. Jellies SUMMARY The heart excitor (HE) motor neuron in the leech Hirudo releases acetylcholine (ACh) and a peptide, FMRFamide, to regulate the contractile activity of the heart tube and associated side vessels. Consistent with Dale's principle, it was assumed that both...

... of the relative speeds of these three waves based on a model of neuromuscular activation and a model of the body–fluid interactions for leech anguilliform-like swimming. First, we deduced the motoneuron spike frequencies that activate the muscle and the resulting muscle tension during swimming in intact leeches...

... and many other functions. In this work, we investigate the distribution and functional properties of I h in identified leech neurons of intact segmental ganglia. We found I h in the mechanosensory touch (T), pressure (P) and noxious (N) neurons, as well as in Retzius neurons. The current displayed its...

...Cynthia M. Harley; Javier Cienfuegos; Daniel A. Wagenaar SUMMARY Medicinal leeches, like many aquatic animals, use water disturbances to localize their prey, so they need to be able to determine if a wave disturbance is created by prey or by another source. Many aquatic predators perform...

... whether LTP undergoes similar changes despite the importance of LTP in learning and memory. Here we report that synapses in the CNS of the medicinal leech demonstrate seasonal variation in the capacity to undergo LTP following paired presynaptic and postsynaptic stimulation. LTP was observed during...

...Jun Chen; Jianghong Tian; Tetsuya Iwasaki; W. Otto Friesen SUMMARY We have studied the dynamical properties of tension development in leech longitudinal muscle during swimming. A new method is proposed for modeling muscle properties under functionally relevant conditions where the muscle...

... species of leeches to stimulation, as the responses are affected by species identity, diet, behavioral state and stimulus location. Our results show that each of the species tested while not feeding displayed remarkably similar behaviors in response to tactile stimulation of the surface of the body. When...

...Angela Wenning; Eric P. Meyer SUMMARY Two tubular, segmented hearts propel blood through the closed circulatory system of the medicinal leech and switch every 20–40 beats between two constriction patterns. We showed recently that within one heartbeat cycle,heart segments on one side constrict...

...Kevin M. Crisp; Karen A. Mesce SUMMARY The biological mechanisms of behavioral selection, as it relates to locomotion, are far from understood, even in relatively simple invertebrate animals. In the medicinal leech, Hirudo medicinalis , the decision to swim is distributed across populations of swim...

... trends are apparent in the nervous system of annelid worms, including leeches. To determine if the anterior brain of the leech serves functions similar to those of the brains of more complex organisms, including vertebrates, we ablated one of the two major regions of the cephalic brain...

...Kevin M. Crisp; Karen A. Mesce SUMMARY It is widely appreciated that the selection and modulation of locomotor circuits are dependent on the actions of higher-order projection neurons. In the leech, Hirudo medicinalis, locomotion is modulated by a number of cephalic projection neurons that descend...

... the dorsal integument of the leech Hirudo medicinalis , and we have established a model of Na + uptake. In the present study, we investigated the effect of long-term acclimation on transintegumental ion transport by adapting leeches to high-salinity conditions. We dissected segments of dorsal integument...