Month: February 2017

Experiment 3: Reconsolidation of Fix-C and Esc-C memory

Administration of MK-801 before the CPP test (pre memory retrieval) prevented a reduction in place preference for Fix-C [F(1,48)=8.904; p=0.004; group effect] but it had no effect on Esc-C (Fig 2.3B,C). For Fix-C, there was a significant time effect [F(2,48)=48.437; p<0.001] and a significant group x…

Experiment 2: Acquisition of Esc-C and Fix-C memory

The effect of the NR2B antagonist ifenprodil on acquisition of place preference was investigated because of the observed increase in NR2B subunit expression in the hippocampus. Additionally, because inhibition of nNOS was shown to block Fix-C memory acquisition (Itzhak et al., 1998) and since nNOS activity…

Immunoblot Analysis

Twenty-four hours after conditioning, mice were tested for the expression of place preference (20min) then sacrificed. Bi-lateral hippocampus was dissected and flash frozen on dry ice. Tissues were homogenized on ice in 200μl RIPA buffer (4.5mM Tris- HCl pH7.4, 150mM NaCl, 1% NP-40, 0.5% sodium deoxycholate,…

Experiment 1: Contribution of NMDAR subunits in formation of Fix-C and Esc-C memory

To determine whether NMDAR subunits were differentially regulated in mice conditioned by Fix-C and Esc-C (Itzhak & Anderson, 2012) we performed quantitative real-time polymerase chain reaction (qPCR) and immunoblot analyses (n=3-4 mice/group). Bilateral hippocampus was dissected 24h after conditioning and subsequently analyzed. In the hippocampus NR2A…

Materials and Methods (Conditioning procedure)

Subjects Male C57BL/6J mice (8 weeks old) were purchased from Jackson Laboratories (Bar Harbor, Maine). Mice were housed in groups of 5/cage with food and water adlibitum and were acclimatized to the vivarium for one week before experiments began. Animal care was in accordance with the…

Research objectives and hypothesis

An important target for combating drug addiction is to understand the neurobiological mechanisms that sub-serve relapse to drug use (Mantsch et al., 2010). Drug addiction is thought to usurp the neural mechanisms of learning and memory (Hyman, 2005) and affect long term plasticity as a result…

Role of nitric oxide in cocaine effects

The observation that nNOS is linked to NMDAR subunits led to studies on the role of nNOS in the effects of cocaine. Chronic cocaine administration increased NOS activity in cerebral cortex, cerebellum, midbrain, hypothalamus, hippocampus, amygdala and spinal cord of Swiss-Webster mice (Bhargava & Kumar, 1997).…

The role of glutamate in drug-induced neuroadaptations

Historically, dopamine has been considered the major neurotransmitter involved in the effects of cocaine and other drugs of abuse. However, more recent studies have shown that the excitatory neurotransmitter glutamate plays a central role in the behavioral and neurochemical effects of cocaine. Neuronal changes associated with…

The conditioned place preference (CPP) paradigm

Learning and memory mechanisms play a major role in the development of maladaptive behaviors, including drug addiction (Hyman et al., 2006). The conditioned place preference (CPP) paradigm, which employs the principles of Pavlovian conditioning, can model learning and memory processes pertinent to addictive behavior (White &…