Journal: Frontiers in Behavioral Neuroscience

Article Title: Dopamine D1/D5 Receptors in the Retrosplenial Cortex Are Necessary to Consolidate Object Recognition Memory

doi: 10.3389/fnbeh.2022.922971

Figure Lengend Snippet: aRSC requires D1/D5 activity for object recognition memory consolidation. Saline (Vehicle, Veh, white bar) or D1/D5 antagonist (SCH23390, SCH, gray bar) was infused into aRSC immediately after training. Graphics show the discrimination index from animals tested (A) 24 h or (B) 3 h after the training session. Data are expressed as mean ± SEM. ** p < 0.01, Veh vs. SCH, two-tailed Student's t -test; ## p < 0.01, ### p < 0.001, Group vs. 0, two-tailed Student's t -test. (A) n = 7, (B) n = 7–8.

Article Snippet: To study the dopaminergic input we infused into the aRSC, the D1/D5 dopamine receptor antagonist SCH23390 hydrochloride (Sigma Aldrich, Germany) and the agonist SKF38393 hydrochloride (Sigma Aldrich, Germany) at a dose of 0.75 μg per side and 12.5 μg per side, respectively.

Techniques: Activity Assay, Two Tailed Test

Journal: Frontiers in Cellular Neuroscience

Article Title: Photostimulation of Ventral Tegmental Area-Insular Cortex Dopaminergic Inputs Enhances the Salience to Consolidate Aversive Taste Recognition Memory via D1-Like Receptors

doi: 10.3389/fncel.2022.823220

Figure Lengend Snippet: Processing of aversive but not appetitive taste requires D1-like receptor activity into insular cortex (IC). Dopaminergic activity blockade in the IC impedes consolidation of aversive but not appetitive taste recognition memory (TRM). (A) ChR2 mice were administered with SCH23390 ( n = 11) or vehicle ( n = 6) before the photostimulation of the ventral tegmental area (VTA) dopaminergic neurons. No statistical significance was shown for consumption index of low saccharin in ChR2 mice/vehicle nor ChR2/SCH23390 mice vs. randomness 0.5 [ChR2/Vehicle mice: one sample t- test, t (5) = 2.077, p = 0.0925; ChR2/SCH23390 mice: one sample t- test, t (10) = 0.8933, p = 0.3927]. During the memory test, both mice groups exhibited a strong preference for the low saccharin solution vs. randomness [ChR2/Vehicle: one sample t- test, t (5) = 5.722, p = 0.0023; ChR2/SCH23390: one sample t- test, t (10) = 9.670, p < 0.0001]. IC coronal plane adapted from . (B) ChR2 mice were administered with SCH23390 ( n = 7) or vehicle ( n = 8) before the photostimulation of the VTA dopaminergic neurons. No statistical significance was shown for consumption index of low quinine in ChR2/Vehicle nor ChR2/SCH23390 vs. randomness 0.5 [ChR2/Vehicle: one sample t- test, t (7) = 2.313, p = 0.0540; ChR2/SCH23390: one sample t- test, t (6) = 1.636, p = 0.1530]. During the memory test, the group administered with SCH23390 before the optogenetic stimulation of the VTA-IC dopaminergic pathway impaired the avoidance behavior for the low quinine solution in the ChR2 mice vs. randomness 0.5 ( n = 7) [one sample t-test , t (7) = 4.489, p = 0.0028] but not in the ChR2 mice administered with vehicle vs. randomness 0.5 ( n = 8) [one sample t- test, t (6) = 1.320, p = 0.2349]. IC coronal plane adapted from . All data are shown as mean ± SEM. ** p < 0.01, *** p < 0.001.

Article Snippet: The next day after the last baseline session, mice were injected into IC with vehicle (0.9% saline solution), or dopamine D1-like receptor antagonist SCH23390 (2 μg/μl, dissolved in 0.9% saline solution, D054, Sigma-Aldrich).

Techniques: Activity Assay

Journal: Frontiers in Cellular Neuroscience

Article Title: Photostimulation of Ventral Tegmental Area-Insular Cortex Dopaminergic Inputs Enhances the Salience to Consolidate Aversive Taste Recognition Memory via D1-Like Receptors

doi: 10.3389/fncel.2022.823220

Figure Lengend Snippet: Ventral tegmental area (VTA) photostimulation increases the salience of conditioned taste aversion for an appetitive taste. (A) ChR2 ( n = 16) or EYFP ( n = 16) mice were photostimulated into VTA when the low saccharin was presented during the training session. No statistical significance was shown for consumption index of low saccharin in EYFP nor ChR2 mice vs. randomness 0.5 [EYFP: one sample t- test, t (15) = 1.550, p = 0.1421; ChR2: one sample t- test, t (15) = 2.793, p = 0.0137]. After the training session, mice were intraperitoneally injected with an unconditioned stimulus NaCl (66 mg/kg) or LiCl (48 mg/kg). The administration of NaCl in ChR2 mice ( n = 7) did not affect the preference for the low saccharin vs. randomness 0.5 due to the photostimulation of the VTA dopaminergic neurons [ChR2-NaCl: one sample t- test, t (6) = 5.109, p = 0.0022] but the consumption in EYFP was not affected [EYFP-NaCl: one sample t- test, t (6) = 0.05799, p = 0.9556]. The administration of LiCl in ChR2 mice decreased the consumption of the low saccharin vs. randomness 0.5 [ChR2-LiCl: one sample t- test, t (8) = 5.930, p = 0.0003], but the consumption of EYFP mice was not affected [EYFP-LiCl: one sample t- test, t (8) = 1.532, p = 0.1640]. (B) Diagram of coronal slice for insular cortex (IC) cannulation in ChR2 mice. SCH23390 ( n = 7) or vehicle ( n = 7) in ChR2 mice was administered before the photostimulation of the VTA dopaminergic neurons. No statistical significance was shown for consumption index of low saccharin in Vehicle/ChR2 mice nor SHC23390/ChR2 mice vs. randomness 0.5 [Vehicle/ChR2: one sample t- test, t (6) = 1.767, p = 0.1276; SCH23390/ChR2: one sample t- test, t (6) = 1.190, p = 0.2791]. Ten minutes later mice were intraperitoneally injected with a low dose of LiCl. The blockage of the D1-like receptors into the IC impairs the consolidation of the conditioned taste aversion in the SCH23390/ChR2 mice [one sample t- test, t (6) = 2.897, p = 0.0274]. In contrast, the vehicle/ChR2 mice showed a reliable conditioned taste aversion [one sample t- test, t (6) = 2.703, p = 0.0355]. IC coronal plane adapted from . All data are shown as mean ± SEM. * p < 0.05; ** p < 0.01.

Article Snippet: The next day after the last baseline session, mice were injected into IC with vehicle (0.9% saline solution), or dopamine D1-like receptor antagonist SCH23390 (2 μg/μl, dissolved in 0.9% saline solution, D054, Sigma-Aldrich).

Techniques: Injection

Journal: Scientific Reports

Article Title: Intrinsic motivation for singing in songbirds is enhanced by temporary singing suppression and regulated by dopamine

doi: 10.1038/s41598-021-99456-w

Figure Lengend Snippet: Effects of systemic injections of dopamine or opioid antagonists on first song latencies after 5-h LO in young adult birds. ( A ) Schedules of drug injections. Drugs or their vehicles were injected at 30-min preceding the offset of 5-h LO periods. ( B ) Comparisons of first song latencies between a dopamine D1 receptor antagonist SCH23390 with lower (0.2 mg/kg, top ) and higher (1 mg/kg, bottom ) doses and its vehicle (‘Veh’). Each line indicates a single bird. Injections of both lower and higher doses significantly increased first song latencies compared to the vehicle (* p = 0.004, significance level α was corrected to 0.0083 with a Holm-Bonferroni correction for multiple comparisons). ( C ) Comparisons between a dopamine D2 receptor antagonist haloperidol with lower (0.2 mg/kg, top ) and higher (1 mg/kg, bottom ) doses and its vehicle. Injections of the higher dose, but not the lower dose, greatly prolonged the first song latencies (* p = 0.008, corrected α = 0.0125). If no song production was observed during the post-LO period (7-h duration), the data was assigned a time of 7 h (420 min, dashed line). ( D ) Comparisons between an opioid antagonist naloxone with lower (2 mg/kg, top ) and higher (10 mg/kg, bottom ) doses and its vehicle. The effects of naloxone were not significant for either dose ( p = 0.04 and corrected α = 0.0167 for lower dose; p = 0.07 and corrected α = 0.025 for higher dose).

Article Snippet: Injected drugs and their doses were as follows: the dopamine D1 receptor antagonist R(+)-SCH23390 (Millipore Sigma, D054) dissolved in 0.9% saline (0.2 and 1.0 mg/kg); the dopamine D2 receptor antagonist haloperidol (Millipore Sigma, H1512) stored as stock solution in DMSO at − 20 °C and diluted in 0.9% saline before injection (0.2 and 1.0 mg/kg); the opioid receptor antagonist naloxone hydrochloride dihydrate (Millipore Sigma, N7758) dissolved in 0.9% saline (2 and 10 mg/kg).

Techniques: Injection