scholarly journals Locus coeruleus patterns differentially modulate learning and valence in rat via the ventral tegmental area and basolateral amygdala respectively

2020 ◽  
Author(s):  
Abhinaba Ghosh ◽  
Faghihe Massaeli ◽  
Kyron D. Power ◽  
Tamunotonye Omoluabi ◽  
Sarah E. Torraville ◽  
...  
Keyword(s):  
Locus Coeruleus ◽  
Ventral Tegmental Area ◽  
Basolateral Amygdala ◽  
Odor Discrimination ◽  
Odor Aversion ◽  
Odor Preference ◽  
Learning Facilitation ◽  
Ventral Tegmental ◽  
Positive Valence ◽  
Tonic Stimulation

ABSTRACTThe locus coeruleus (LC), the main source of forebrain norepinephrine, produces phasic and tonic firing patterns that are theorized to have distinct functional consequences. However, how different firing modes affect learning and valence coding of sensory information are unknown. Here bilateral optogenetic activation of rat LC neurons using 10-Hz phasic trains of either 300 msec or 10 sec accelerates acquisition of a food-rewarded similar odor discrimination, but not a dissimilar odor discrimination, consistent with LC-supported enhanced pattern separation and plasticity. Similar odor discrimination learning is impaired by noradrenergic blockade in the piriform cortex (PC). However, here 10-Hz LC phasic light-mediated learning facilitation is prevented by a dopaminergic antagonist in the PC, or by ventral tegmental area (VTA) silencing with lidocaine, suggesting an LC-VTA-PC dopamine circuitry mediates 10-Hz phasic learning facilitation. Tonic stimulation at 10 Hz did not alter odor discrimination acquisition, and was less effective in activating VTA DA neurons. For valence encoding, tonic stimulation at 25 Hz induced freezing, anxiety and conditioned odor aversion, while 10-Hz phasic stimulation produced an odor preference consistent with positive valence. Noradrenergic blockade in the basolateral amygdala (BLA) prevented conditioned odor preference and aversion induced by 10-Hz phasic and 25-Hz tonic light respectively. CTB retro-labeling showed relatively larger engagement of nucleus accumbens projecting neurons over central amygdala projecting neurons in the BLA with 10-Hz LC phasic activation, compared to 25-Hz tonic. These outcomes argue that LC pauses, as well as LC firing frequencies, differentially influence both target networks and behaviour.

scholarly journals Locus Coeruleus Activation Patterns Differentially Modulate Odor Discrimination Learning and Odor Valence in Rats

2021 ◽  
Author(s):  
Abhinaba Ghosh ◽  
Faghihe Massaeli ◽  
Kyron D Power ◽  
Tamunotonye Omoluabi ◽  
Sarah E Torraville ◽  
...  
Keyword(s):  
Locus Coeruleus ◽  
Discrimination Learning ◽  
Basolateral Amygdala ◽  
Piriform Cortex ◽  
Sensory Information ◽  
Odor Discrimination ◽  
Mediated Learning ◽  
Odor Aversion ◽  
Activation Patterns ◽  
Tonic Stimulation

Abstract The locus coeruleus (LC) produces phasic and tonic firing patterns that are theorized to have distinct functional consequences. However, how different firing modes affect learning and valence encoding of sensory information are unknown. Here we show bilateral optogenetic activation of rat LC neurons using 10-Hz phasic trains of either 300 msec or 10 sec accelerated acquisition of a similar odor discrimination. Similar odor discrimination learning was impaired by noradrenergic blockade in the piriform cortex (PC). However, 10-Hz phasic light-mediated learning facilitation was prevented by a dopaminergic antagonist in the PC, or by ventral tegmental area (VTA) silencing with lidocaine, suggesting a LC-VTA-PC dopamine circuitry involvement. Ten hertz tonic stimulation did not alter odor discrimination acquisition, and was ineffective in activating VTA DA neurons. For valence encoding, tonic stimulation at 25 Hz induced conditioned odor aversion, while 10-Hz phasic stimulations produced an odor preference. Both conditionings were prevented by noradrenergic blockade in the basolateral amygdala (BLA). Cholera Toxin B retro-labeling showed larger engagement of nucleus accumbens-projecting neurons in the BLA with 10-Hz phasic activation, and larger engagement of central amygdala projecting cells with 25-Hz tonic light. These outcomes argue that the LC activation patterns differentially influence both target networks and behavior.

scholarly journals Morphine selectively promotes glutamate release from glutamatergic terminals of projection neurons from medial prefrontal cortex to dopamine neurons of ventral tegmental area

2017 ◽  
Author(s):  
Li Yang ◽  
Ming Chen ◽  
Ping Zheng
Keyword(s):  
Prefrontal Cortex ◽  
Locomotor Activity ◽  
Ventral Tegmental Area ◽  
Medial Prefrontal Cortex ◽  
Lateral Hypothalamus ◽  
Basolateral Amygdala ◽  
Glutamate Release ◽  
Dopamine Neurons ◽  
Projection Neurons ◽  
Ventral Tegmental

AbstractRecently, we found that morphine promoted presynaptic glutamate release of dopamine (DA) neurons in the ventral tegmental area (VTA), which constituted the main mechanism for morphine-induced increase in VTA-DA neuron firing and related behaviors (Chen et al., 2015). However, what source of presynaptic glutamate release of DA neurons in the VTA is promoted by morphine remains unknown. To address this question, we used optogenetic strategy to selectively activate glutamatergic inputs from different projection neurons and then observed the effect of morphine on them. The result shows that morphine promotes glutamate release from glutamatergic terminals of projection neurons from the medial prefrontal cortex (mPFC) to VTA DA neurons, but has no effect on that from the basolateral amygdala (BLA) or the lateral hypothalamus (LH) to VTA DA neurons, and the inhibition of glutamatergic projection neurons from the mPFC to the VTA significantly reduces morphine-induced increase in locomotor activity of mice.

scholarly journals Comparison of the VTA and LC response to methylphenidate: a concomitant behavioral and neuronal study of adolescent male rats

2017 ◽  
Vol 118 (3) ◽  
pp. 1501-1514 ◽  
Author(s):  
Tahseen J. Karim ◽  
Cruz Reyes-Vazquez ◽  
Nachum Dafny
Keyword(s):  
Locus Coeruleus ◽  
Ventral Tegmental Area ◽  
Neuronal Activity ◽  
Behavioral Sensitization ◽  
Neuronal Response ◽  
Normal Subjects ◽  
Male Rats ◽  
Adolescent Male ◽  
Adolescent Rats ◽  
Ventral Tegmental

Methylphenidate (MPD), also known as Ritalin, is a psychostimulant used to treat attention deficit hyperactivity disorder. However, it is increasingly being misused by normal adolescents for recreation and academic advantage. Therefore, it is important to elucidate the behavioral and neurophysiological effects of MPD in normal subjects. MPD inhibits the reuptake of catecholamines, mainly found in the ventral tegmental area (VTA) and locus coeruleus (LC). The VTA and LC normally mediate attention, motivation, and drug reward behaviors. Selective neuronal connections between the VTA and LC have been identified implicating regular interaction between the structures. The objective of this study was to compare the neuronal responses of the VTA and LC to MPD in normal adolescent rats. Animals were implanted with permanent electrodes in the VTA and LC, and neuronal units were recorded following acute and repetitive (chronic) saline or 0.6, 2.5, or 10.0 mg/kg MPD exposure. Animals displayed either behavioral sensitization or tolerance to all three doses of MPD. Acute MPD exposure elicited excitation in the majority of all VTA and LC units. Chronic MPD exposure elicited a further increase in VTA and LC neuronal activity in animals exhibiting behavioral sensitization and an attenuation in VTA and LC neuronal activity in animals exhibiting behavioral tolerance, demonstrating neurophysiological sensitization and tolerance, respectively. The similar pattern in VTA and LC unit activity suggests that the two structures are linked in their response to MPD. These results may help determine the exact mechanism of action of MPD, resulting in optimized treatment of patients. NEW & NOTEWORTHY The same dose of 0.6, 2.5, and 10 mg/kg methylphenidate (MPD) elicits either behavioral sensitization or tolerance in adolescent rats. There is a direct correlation between the ventral tegmental area (VTA) and locus coeruleus (LC) neuronal response to chronic MPD exposure. Both the VTA and LC are involved in the behavioral and neurophysiological effects of chronic MPD.

scholarly journals Mind-Body Exercise Modulates Locus Coeruleus and Ventral Tegmental Area Functional Connectivity in Individuals With Mild Cognitive Impairment

2021 ◽  
Vol 13 ◽  
Author(s):  
Jiao Liu ◽  
Jing Tao ◽  
Rui Xia ◽  
Moyi Li ◽  
Maomao Huang ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Functional Connectivity ◽  
Locus Coeruleus ◽  
Ventral Tegmental Area ◽  
Control Group ◽  
Brisk Walking ◽  
Area Functional ◽  
Ventral Tegmental ◽  
The Right

Mild cognitive impairment (MCI) is a common global health problem. Recently, the potential of mind-body intervention for MCI has drawn the interest of investigators. This study aims to comparatively explore the modulation effect of Baduanjin, a popular mind-body exercise, and physical exercise on the cognitive function, as well as the norepinephrine and dopamine systems using the resting state functional connectivity (rsFC) method in patients with MCI. 69 patients were randomized to the Baduanjin, brisk walking, or healthy education control group for 6 months. The Montreal Cognitive Assessment (MoCA) and magnetic resonance imaging (MRI) scans were applied at baseline and at the end of the experiment. Results showed that (1) compared to the brisk walking, the Baduanjin significantly increased MoCA scores; (2) Baduanjin significantly increased the right locus coeruleus (LC) and left ventral tegmental area (VTA) rsFC with the right insula and right amygdala compared to that of the control group; and the right anterior cingulate cortex (ACC) compared to that of the brisk walking group; (3) the increased right LC-right insula rsFC and right LC-right ACC rsFC were significantly associated with the corresponding MoCA score after 6-months of intervention; (4) both exercise groups experienced an increased effective connectivity from the right ACC to the left VTA compared to the control group; and (5) Baduanjin group experienced an increase in gray matter volume in the right ACC compared to the control group. Our results suggest that Baduanjin can significantly modulate intrinsic functional connectivity and the influence of the norepinephrine (LC) and dopamine (VTA) systems. These findings may shed light on the mechanisms of mind-body intervention and aid the development of new treatments for MCI.

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