38 research outputs found
Dopamine D1-like receptor signalling in the hippocampus and amygdala modulates the acquisition of contextual fear conditioning
RATIONALE: Dopamine D1-like receptor signalling is involved in contextual fear conditioning, but the brain regions involved and its role in other contextual fear memory processes remain unclear.
OBJECTIVES: The objective of this study was to investigate (1) the effects of SCH 23390, a dopamine D1/D5 receptor antagonist, on contextual fear memory encoding, retrieval and reconsolidation, and (2) if the effects of SCH 23390 on conditioning involve the dorsal hippocampus (DH) and/or basolateral amygdala (BLA).
METHODS: Rats were used to examine the effects of systemically administering SCH 23390 on the acquisition, consolidation, retrieval and reconsolidation of contextual fear memory, and on locomotor activity and shock sensitivity. We also determined the effects of MK-801, an NMDA receptor antagonist, on contextual fear memory reconsolidation. The effects of infusing SCH 23390 locally into DH or BLA on contextual fear conditioning and locomotor activity were also examined.
RESULTS: Systemic administration of SCH 23390 impaired contextual fear conditioning but had no effects on fear memory consolidation, retrieval or reconsolidation. MK-801 was found to impair reconsolidation, suggesting that the behavioural parameters used allowed for the pharmacological disruption of memory reconsolidation. The effects of SCH 23390 on conditioning were unlikely the result of any lasting drug effects on locomotor activity at memory test or any acute drug effects on shock sensitivity during conditioning. SCH 23390 infused into either DH or BLA impaired contextual fear conditioning and decreased locomotor activity.
CONCLUSIONS: These findings suggest that dopamine D1-like receptor signalling in DH and BLA contributes to the acquisition of contextual fear memory
Evaluation of a wide-band method for the measurement of the reflection coefficient of microwave one-port networks
NRC publication: Ye
A coaxial calorimeter and its use as a reference standard in an automated microwave power calibration system
NRC publication: Ye
A semi-automatic method for the precision measurement of microwave impedance
NRC publication: Ye
International comparison GT-RF 75-B3: reflection coefficient at 300 MHz, 600 MHz and 1000 MHz in 75 [omega] coaxial line
NRC publication: Ye
International comparison GT-RF 78-14: power (1 mW) at 50 MHz in 50-[omega] coaxial line
NRC publication: Ye
National standards and standard measurement systems for impedance and reflection coefficient
NRC publication: Ye
International comparison GT-RF 75-B3: reflection coefficient at 300, 600 and 1000 MHz in 75 ohm coaxial line
NRC publication: Ye