Chronic low-amplitude electrical stimulation of the laterodorsal tegmental nucleus of freely moving cats increases REM sleep

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.

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Electrical stimulation of retinal neurons in epiretinal and subretinal configuration using a multicapacitor array

Journal of Neurophysiology ◽

10.1152/jn.00909.2011 ◽

2012 ◽

Vol 107 (10) ◽

pp. 2742-2755 ◽

Cited By ~ 79

Author(s):

Max Eickenscheidt ◽

Martin Jenkner ◽

Roland Thewes ◽

Peter Fromherz ◽

Günther Zeck

Keyword(s):

Electrical Stimulation ◽

Ganglion Cells ◽

Ex Vivo ◽

Biophysical Model ◽

Retinal Neurons ◽

Direct Stimulation ◽

Tungsten Electrode ◽

Partial Restoration ◽

Low Amplitude ◽

Stimulation Of

Electrical stimulation of retinal neurons offers the possibility of partial restoration of visual function. Challenges in neuroprosthetic applications are the long-term stability of the metal-based devices and the physiological activation of retinal circuitry. In this study, we demonstrate electrical stimulation of different classes of retinal neurons with a multicapacitor array. The array—insulated by an inert oxide—allows for safe stimulation with monophasic anodal or cathodal current pulses of low amplitude. Ex vivo rabbit retinas were interfaced in either epiretinal or subretinal configuration to the multicapacitor array. The evoked activity was recorded from ganglion cells that respond to light increments by an extracellular tungsten electrode. First, a monophasic epiretinal cathodal or a subretinal anodal current pulse evokes a complex burst of action potentials in ganglion cells. The first action potential occurs within 1 ms and is attributed to direct stimulation. Within the next milliseconds additional spikes are evoked through bipolar cell or photoreceptor depolarization, as confirmed by pharmacological blockers. Second, monophasic epiretinal anodal or subretinal cathodal currents elicit spikes in ganglion cells by hyperpolarization of photoreceptor terminals. These stimuli mimic the photoreceptor response to light increments. Third, the stimulation symmetry between current polarities (anodal/cathodal) and retina-array configuration (epi/sub) is confirmed in an experiment in which stimuli presented at different positions reveal the center-surround organization of the ganglion cell. A simple biophysical model that relies on voltage changes of cell terminals in the transretinal electric field above the stimulation capacitor explains our results. This study provides a comprehensive guide for efficient stimulation of different retinal neuronal classes with low-amplitude capacitive currents.

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Effects of the 5-HT1A receptor ligands flesinoxan and WAY 100635 given systemically or microinjected into the laterodorsal tegmental nucleus on REM sleep in the rat

Behavioural Brain Research ◽

10.1016/j.bbr.2003.08.023 ◽

2004 ◽

Vol 151 (1-2) ◽

pp. 159-166 ◽

Cited By ~ 21

Author(s):

Jaime M Monti ◽

Héctor Jantos

Keyword(s):

Rem Sleep ◽

Receptor Ligands ◽

Laterodorsal Tegmental Nucleus ◽

Tegmental Nucleus ◽

Way 100635

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Cholinergic influence of the laterodorsal tegmental nucleus on neuronal activity in the rat lateral geniculate nucleus

Journal of Neurophysiology ◽

10.1152/jn.1986.56.5.1297 ◽

1986 ◽

Vol 56 (5) ◽

pp. 1297-1309 ◽

Cited By ~ 41

Author(s):

Y. Kayama ◽

M. Takagi ◽

T. Ogawa

Keyword(s):

Brain Stem ◽

Lateral Geniculate Nucleus ◽

Cholinergic Neurons ◽

Photic Stimulation ◽

Dorsal Lateral Geniculate Nucleus ◽

Laterodorsal Tegmental Nucleus ◽

Tegmental Nucleus ◽

Lateral Geniculate ◽

Stimulation Of ◽

Relay Neurons

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.

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