ELECTROPHYSIOLOGICAL CHARACTERISTICS OF PARAVENTRICULAR THALAMIC (PVT) NEURONS IN RESPONSE TO CHRONIC COCAINE EXPOSURE: EFFECTS OF COCAINE- AND AMPHETAMINE-REGULATED TRANSCRIPT (CART)
Recent work has established that the paraventricular thalamus (PVT) is a central node in the brain reward-seeking pathway. This role is likely mediated in part through the dense projections to the PVT from hypothalamic peptide transmitter systems such as orexin, and cocaine- and amphetamine-regulate...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2014-08-01
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| Series: | Frontiers in Behavioral Neuroscience |
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| Online Access: | http://journal.frontiersin.org/Journal/10.3389/fnbeh.2014.00280/full |
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| author | Jiann Wei eYeoh Morgan H James Brett A Graham Christopher V Dayas |
| author_facet | Jiann Wei eYeoh Morgan H James Brett A Graham Christopher V Dayas |
| author_sort | Jiann Wei eYeoh |
| collection | DOAJ |
| description | Recent work has established that the paraventricular thalamus (PVT) is a central node in the brain reward-seeking pathway. This role is likely mediated in part through the dense projections to the PVT from hypothalamic peptide transmitter systems such as orexin, and cocaine- and amphetamine-regulated transcript (CART), both of which play key roles in drug-seeking behaviour. Consistent with this proposition, we previously found that inactivation of the PVT or infusions of CART into the PVT suppressed drug-seeking behaviour in an animal model of contingent cocaine self-administration. Despite this work, very few studies have assessed the basic physiological properties of PVT neurons and how these parameters are altered by exposure to drugs such as cocaine. We set out to address these questions by employing an electrophysiological approach to record from anterior PVT (aPVT) neurons from cocaine-treated and control animals. First, we determined the excitability of aPVT neurons by injecting a series of depolarizing current steps and characterizing the resulting action potential (AP) discharge properties. Second, we investigated the effects of CART on excitatory synaptic inputs to aPVT neurons. We found that the majority of aPVT neurons exhibited tonic firing (TF), and initial bursting (IB) consistent with previous studies. However, we also identified PVT neurons that exhibited delayed firing (DF), single spiking (SS) and reluctant firing (RF). Interestingly, cocaine exposure shifted the proportion of aPVT neurons that exhibited TF. Further, application of CART suppressed excitatory synaptic drive to PVT. This finding is consistent with our previous behavioural data, which showed that CART signaling in the PVT negatively regulates drug-seeking behaviour. Together, these studies support previous anatomical evidence that the PVT can integrate reward-relevant information and provides a putative mechanism through which drugs of abuse can dysregulate this system in addiction. |
| first_indexed | 2024-04-12T01:14:36Z |
| format | Article |
| id | doaj.art-8e4a99efe4924ae9a87202cda71b35fd |
| institution | Directory Open Access Journal |
| issn | 1662-5153 |
| language | English |
| last_indexed | 2024-04-12T01:14:36Z |
| publishDate | 2014-08-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Behavioral Neuroscience |
| spelling | doaj.art-8e4a99efe4924ae9a87202cda71b35fd2022-12-22T03:54:01ZengFrontiers Media S.A.Frontiers in Behavioral Neuroscience1662-51532014-08-01810.3389/fnbeh.2014.0028094759ELECTROPHYSIOLOGICAL CHARACTERISTICS OF PARAVENTRICULAR THALAMIC (PVT) NEURONS IN RESPONSE TO CHRONIC COCAINE EXPOSURE: EFFECTS OF COCAINE- AND AMPHETAMINE-REGULATED TRANSCRIPT (CART)Jiann Wei eYeoh0Morgan H James1Brett A Graham2Christopher V Dayas3The University of NewcastleThe University of NewcastleThe University of NewcastleThe University of NewcastleRecent work has established that the paraventricular thalamus (PVT) is a central node in the brain reward-seeking pathway. This role is likely mediated in part through the dense projections to the PVT from hypothalamic peptide transmitter systems such as orexin, and cocaine- and amphetamine-regulated transcript (CART), both of which play key roles in drug-seeking behaviour. Consistent with this proposition, we previously found that inactivation of the PVT or infusions of CART into the PVT suppressed drug-seeking behaviour in an animal model of contingent cocaine self-administration. Despite this work, very few studies have assessed the basic physiological properties of PVT neurons and how these parameters are altered by exposure to drugs such as cocaine. We set out to address these questions by employing an electrophysiological approach to record from anterior PVT (aPVT) neurons from cocaine-treated and control animals. First, we determined the excitability of aPVT neurons by injecting a series of depolarizing current steps and characterizing the resulting action potential (AP) discharge properties. Second, we investigated the effects of CART on excitatory synaptic inputs to aPVT neurons. We found that the majority of aPVT neurons exhibited tonic firing (TF), and initial bursting (IB) consistent with previous studies. However, we also identified PVT neurons that exhibited delayed firing (DF), single spiking (SS) and reluctant firing (RF). Interestingly, cocaine exposure shifted the proportion of aPVT neurons that exhibited TF. Further, application of CART suppressed excitatory synaptic drive to PVT. This finding is consistent with our previous behavioural data, which showed that CART signaling in the PVT negatively regulates drug-seeking behaviour. Together, these studies support previous anatomical evidence that the PVT can integrate reward-relevant information and provides a putative mechanism through which drugs of abuse can dysregulate this system in addiction.http://journal.frontiersin.org/Journal/10.3389/fnbeh.2014.00280/fullCocaineElectrophysiologyAddictionreward seekingparaventricular nucleus of the thalamusCART |
| spellingShingle | Jiann Wei eYeoh Morgan H James Brett A Graham Christopher V Dayas ELECTROPHYSIOLOGICAL CHARACTERISTICS OF PARAVENTRICULAR THALAMIC (PVT) NEURONS IN RESPONSE TO CHRONIC COCAINE EXPOSURE: EFFECTS OF COCAINE- AND AMPHETAMINE-REGULATED TRANSCRIPT (CART) Frontiers in Behavioral Neuroscience Cocaine Electrophysiology Addiction reward seeking paraventricular nucleus of the thalamus CART |
| title | ELECTROPHYSIOLOGICAL CHARACTERISTICS OF PARAVENTRICULAR THALAMIC (PVT) NEURONS IN RESPONSE TO CHRONIC COCAINE EXPOSURE: EFFECTS OF COCAINE- AND AMPHETAMINE-REGULATED TRANSCRIPT (CART) |
| title_full | ELECTROPHYSIOLOGICAL CHARACTERISTICS OF PARAVENTRICULAR THALAMIC (PVT) NEURONS IN RESPONSE TO CHRONIC COCAINE EXPOSURE: EFFECTS OF COCAINE- AND AMPHETAMINE-REGULATED TRANSCRIPT (CART) |
| title_fullStr | ELECTROPHYSIOLOGICAL CHARACTERISTICS OF PARAVENTRICULAR THALAMIC (PVT) NEURONS IN RESPONSE TO CHRONIC COCAINE EXPOSURE: EFFECTS OF COCAINE- AND AMPHETAMINE-REGULATED TRANSCRIPT (CART) |
| title_full_unstemmed | ELECTROPHYSIOLOGICAL CHARACTERISTICS OF PARAVENTRICULAR THALAMIC (PVT) NEURONS IN RESPONSE TO CHRONIC COCAINE EXPOSURE: EFFECTS OF COCAINE- AND AMPHETAMINE-REGULATED TRANSCRIPT (CART) |
| title_short | ELECTROPHYSIOLOGICAL CHARACTERISTICS OF PARAVENTRICULAR THALAMIC (PVT) NEURONS IN RESPONSE TO CHRONIC COCAINE EXPOSURE: EFFECTS OF COCAINE- AND AMPHETAMINE-REGULATED TRANSCRIPT (CART) |
| title_sort | electrophysiological characteristics of paraventricular thalamic pvt neurons in response to chronic cocaine exposure effects of cocaine and amphetamine regulated transcript cart |
| topic | Cocaine Electrophysiology Addiction reward seeking paraventricular nucleus of the thalamus CART |
| url | http://journal.frontiersin.org/Journal/10.3389/fnbeh.2014.00280/full |
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