Penile erection and micturition events triggered by electrical stimulation of the mesopontine tegmental area

2008 ◽  
Vol 294 (1) ◽  
pp. R102-R111 ◽  
Author(s):  
Juan Carlos Toledo Salas ◽  
Hiroshi Iwasaki ◽  
Eiichi Jodo ◽  
Markus H. Schmidt ◽  
Akihiro Kawauchi ◽  
...  

The cholinergic neurons in the laterodorsal tegmental nucleus (LDT) play a crucial role in the regulation of rapid eye movement (REM) sleep. Because penile erection occurs during REM sleep, the involvement of the LDT in penile erection was examined in unanesthetized head-restrained rats. To detect penile erection, corpus spongiosum of the penis (CSP) pressure was measured through a telemetric device with simultaneous bulbospongiosum (BS) muscle EMG recording through stainless wires. Electrical stimulation in and around the LDT induced the following three CSP pressure patterns: 1) a full erection pattern indistinguishable from the nonevoked or spontaneous erection, characterized by a slow increase in CSP pressure with additional sharp CSP peaks associated with BS muscle bursts, 2) a muscular pattern characterized by sharp CSP pressure peaks but in the absence of a vascular component, i.e., without an increase in baseline CSP pressure, and 3) a mixed-type response characterized by high-frequency CSP pressure peaks followed by a full erection response. Full erections were evoked in and around the LDT, including more medially and ventrally. The sites for inducing mixed-type events were intermingled with the sites that triggered full erections in the anterior half of the LDT, whereas they were separated in the posterior half. The sites for muscular responses were lateral to the sites for full erections. Finally, a CSP pressure response identical to micturition was evoked in and around the Barrington's nucleus and in the dorsal raphe nucleus. These results suggest that the LDT and surrounding region are involved in the regulation of penile erection. Moreover, different anatomical areas in the mesopontine tegmentum may have specific roles in the regulation of penile erection and micturition.

SLEEP ◽  
2010 ◽  
Vol 33 (7) ◽  
pp. 919-929 ◽  
Author(s):  
Dario Brambilla ◽  
Isabella Barajon ◽  
Susanna Bianchi ◽  
Mark R. Opp ◽  
Luca Imeri

1986 ◽  
Vol 56 (5) ◽  
pp. 1297-1309 ◽  
Author(s):  
Y. Kayama ◽  
M. Takagi ◽  
T. Ogawa

The effect of stimulation of the laterodorsal tegmental nucleus (LDT) on the activity of single neurons in the dorsal lateral geniculate nucleus was studied in rats anesthetized with urethan. The LDT is the largest aggregation of cholinergic neurons in the brain stem that project to the thalamus, and in the rat is sufficiently compact to permit its localized stimulation. Position of stimulating electrodes was confirmed on histological sections processed with NADPH-diaphorase histochemistry, which in the rat brain stem selectively stains cholinergic neurons. Repetitive stimulation of the LDT at 200 Hz increased the firing rate of substantially all geniculate relay neurons and weakly depressed the activity of intrinsic interneurons. These effects usually occurred within several hundred milliseconds after the onset of stimulation and began to fade within a few seconds, despite continuing stimulation. The excitatory effects on relay neurons were blocked by scopolamine applied ionophoretically or intravenously, but not by noradrenergic antagonists, suggesting the cholinergic nature of LDT-induced excitation. During LDT stimulation the number of spikes evoked by photic stimulation of the receptive field of relay neurons usually increased, but it remained unchanged in a few cases. The increase was due to simple enhancement of photic responses or due to conversion of phasic type responses to tonic ones. As to the balance of background activity and photic responses, the effects of LDT stimulation varied from neuron to neuron. Even in a given neuron, the effects varied depending on its excitability level or the nature of the photic stimulation. These results show that the cholinergic projection from the LDT may be involved in the ascending reticular activating system, although the functional significance of the activating system in visual information processing in the geniculate nucleus remains to be clarified.


1999 ◽  
Vol 271 (1) ◽  
pp. 53-56 ◽  
Author(s):  
Keiko Ikemoto ◽  
Kunio Kitahama ◽  
Toshihiro Maeda ◽  
Michel Jouvet ◽  
Ikuko Nagatsu

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Icnelia Huerta-Ocampo ◽  
Daniel Dautan ◽  
Nadine K. Gut ◽  
Bakhtawer Khan ◽  
Juan Mena-Segovia

AbstractThe cholinergic midbrain is involved in a wide range of motor and cognitive processes. Cholinergic neurons of the pedunculopontine (PPN) and laterodorsal tegmental nucleus (LDT) send long-ranging axonal projections that target sensorimotor and limbic areas in the thalamus, the dopaminergic midbrain and the striatal complex following a topographical gradient, where they influence a range of functions including attention, reinforcement learning and action-selection. Nevertheless, a comprehensive examination of the afferents to PPN and LDT cholinergic neurons is still lacking, partly due to the neurochemical heterogeneity of this region. Here we characterize the whole-brain input connectome to cholinergic neurons across distinct functional domains (i.e. PPN vs LDT) using conditional transsynaptic retrograde labeling in ChAT::Cre male and female rats. We reveal that input neurons are widely distributed throughout the brain but segregated into specific functional domains. Motor related areas innervate preferentially the PPN, whereas limbic related areas preferentially innervate the LDT. The quantification of input neurons revealed that both PPN and LDT receive similar substantial inputs from the superior colliculus and the output of the basal ganglia (i.e. substantia nigra pars reticulata). Notably, we found that PPN cholinergic neurons receive preferential inputs from basal ganglia structures, whereas LDT cholinergic neurons receive preferential inputs from limbic cortical areas. Our results provide the first characterization of inputs to PPN and LDT cholinergic neurons and highlight critical differences in the connectome among brain cholinergic systems thus supporting their differential roles in behavior.


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