Two critical periods of protein and glycoprotein synthesis in memory consolidation for visual categorization learning in chicks.

Abstract

A protein synthesis inhibitor, anisomycin (ANI), and an inhibitor of glycoprotein synthesis, 2-deoxygalactose (2-D-gal), were used to investigate memory consolidation following visual categorization training in 2-day-old chicks. ANI (0.6 pmole/chick) and 2-D-gal (40 lamoles/chick) were injected intracerebrally at different time intervals from 1 hr before to 23 hr after the training. Retention was tested 24 hr post-training. Both ANI and 2-D-gal injections revealed two periods of memory sensitivity to pharmacological intervention. ANI impaired retention when injected from 5 min before to 30 min after the training or from 4 hr to 5 hr post-training, thus demonstrating that consolidation of long-term memory in this task requires two periods of protein synthesis. 2-D-Gal first produced an amnesia when it was injected in the interval from 5 min before to 5 min after the training. Injections made between 5 min and 5 hr post-training were without effect on the retention. The second period of memory impairment by 2-D-gal started at 5 hr post-training and lasted until 21 hr after the training. Administration of 2-D-gal made 23 hr after the training did not influence retention in the test at either 24 hr or 26 hr. These results are consistent 3Corresponding author.with the hypothesis that two waves of protein and glycoprotein synthesis are necessary for the formation of long-term memory. The prolonged duration of performance impairment by 2-D-gal in the present task might reflect an extended memory consolidation period for a categorization form of learning.

Inhibition of hippocampal protein synthesis following recall disrupts expression of episodic-like memory in trace conditioning

“…This is consistent with several previous studies that have repeatedly demonstrated that inhibition of protein synthesis 6 h or longer following training (in the absence of a recall trial) does not disrupt memory consolidation of the training event (Squire et al, 1975;Tiunova et al, 1998;Nader et al, 2000). Therefore, it is unlikely that inhibition of hippocampal protein synthesis 24 h following the two-training session protocol interferes with consolidation of the original training event, but that its effect was as a result of the reactivation of this robust memory.…”

The Human Synaptic Vesicle Protein, SV2A, Functions as a Galactose Transporter in Saccharomyces cerevisiae

“…Galactose is incorporated into complex oligosaccharides of membrane and secretory glycoproteins in the Golgi, but galactose and some of its derivatives can also be added to proteins in the cytosol as transient or permanent posttranslational modifications (14). The galactose-containing disaccharide, fucose-␣(1-2)galactose, has been implicated in memory formation, learning, and synaptic plasticity (15)(16)(17)(18)(19)(20)(21). Fucose-␣(1-2)galactose sugars are enriched on glycoproteins in presynaptic nerve terminals (22), and it has been shown that fucose-␣(1-2)-galactose modification has profound effects on the expression and degradation of the synaptic vesicle-associated protein, synapsin (22).…”

God's Organism? The Chick as a Model System for Memory Studies

“…Cherkin (1969) developed a one-trial passive avoidance learning task based on the young chick's tendency to peck at small bright objects such as beads, which is discussed in more detail below. In an appetitive visual discrimination task, the chick learns to distinguish food crumbs scattered on the floor of its pen from rather similar pebbles or beads glued to the surface (Andrew and Rogers 1972;Tiunova et al 1998). Isolated chicks will quickly learn a simple maze to rejoin their hatchmates (Gilbert et al 1989;Regolin and Rose 1999).…”