Lesions of the Fasciculus Retroflexus Alter Footshock-Induced cFos Expression in the Mesopontine Rostromedial Tegmental Area of Rats
Open Access
- 12 April 2013
- journal article
- research article
- Published by Public Library of Science (PLoS) in PLOS ONE
- Vol. 8 (4), e60678
- https://doi.org/10.1371/journal.pone.0060678
Abstract
Midbrain dopamine neurons are an essential part of the circuitry underlying motivation and reinforcement. They are activated by rewards or reward-predicting cues and inhibited by reward omission. The lateral habenula (lHb), an epithalamic structure that forms reciprocal connections with midbrain dopamine neurons, shows the opposite response being activated by reward omission or aversive stimuli and inhibited by reward-predicting cues. It has been hypothesized that habenular input to midbrain dopamine neurons is conveyed via a feedforward inhibitory pathway involving the GABAergic mesopontine rostromedial tegmental area. Here, we show that exposing rats to low-intensity footshock (four, 0.5 mA shocks over 20 min) induces cFos expression in the rostromedial tegmental area and that this effect is prevented by lesions of the fasciculus retroflexus, the principal output pathway of the habenula. cFos expression is also observed in the medial portion of the lateral habenula, an area that receives dense DA innervation via the fr and the paraventricular nucleus of the thalamus, a stress sensitive area that also receives dopaminergic input. High-intensity footshock (120, 0.8 mA shocks over 40 min) also elevates cFos expression in the rostromedial tegmental area, medial and lateral aspects of the lateral habenula and the paraventricular thalamus. In contrast to low-intensity footshock, increases in cFos expression within the rostromedial tegmental area are not altered by fr lesions suggesting a role for non-habenular inputs during exposure to highly aversive stimuli. These data confirm the involvement of the lateral habenula in modulating the activity of rostromedial tegmental area neurons in response to mild aversive stimuli and suggest that dopamine input may contribute to footshock- induced activation of cFos expression in the lateral habenulaKeywords
This publication has 72 references indexed in Scilit:
- Input-specific control of reward and aversion in the ventral tegmental areaNature, 2012
- Input to the Lateral Habenula from the Basal Ganglia Is Excitatory, Aversive, and Suppressed by SerotoninNeuron, 2012
- Electrical stimulation of the lateral habenula produces an inhibitory effect on sucrose self-administrationNeuropharmacology, 2011
- Electrical stimulation of the lateral habenula produces enduring inhibitory effect on cocaine seeking behaviorNeuropharmacology, 2010
- The habenula: from stress evasion to value-based decision-makingNature Reviews Neuroscience, 2010
- Two types of dopamine neuron distinctly convey positive and negative motivational signalsNature, 2009
- The Rostromedial Tegmental Nucleus (RMTg), a GABAergic Afferent to Midbrain Dopamine Neurons, Encodes Aversive Stimuli and Inhibits Motor ResponsesNeuron, 2009
- The mesopontine rostromedial tegmental nucleus: A structure targeted by the lateral habenula that projects to the ventral tegmental area of Tsai and substantia nigra compactaJournal of Comparative Neurology, 2009
- Representation of negative motivational value in the primate lateral habenulaNature Neuroscience, 2008
- Glutamate synaptic inputs to ventral tegmental area neurons in the rat derive primarily from subcortical sourcesNeuroscience, 2007