Thinking Crickets: 'Cognitive' Processes Underlie Memory Recall In Crickets
Activation of two different kinds of neurons is necessary for appetitive and aversive memory recall in crickets. Researchers blocked octopaminergic (OA-ergic) and dopaminergic (DA-ergic) transmission and found that this resulted in the inability to recall pleasant and unpleasant memories, respectively…. (more @ ScienceDaily)
Hello Toronto! I’m in town for the APA conference (yes, the American Psychological Association is having its annual meeting in Canada).
Check out my photos from when I was in Toronto this past December.
Also, here’s what I’ll be presenting:
BACKGROUND: Systemic exposure to amphetamine (AMPH) leads to a number of long-lasting neuroadaptations including changes in dendritic morphology in rat forebrain. It remains unknown whether these changes relate to associative drug conditioning or to nonassociative drug sensitization, two forms of plasticity produced by systemic exposure to AMPH. METHODS: We compared the behavioral, neuronal, and morphologic consequences of exposing rats to intraperitoneal (IP) AMPH to those of exposure to AMPH applied to the ventral tegmental area (VTA), infusions that sensitize AMPH-induced locomotion and nucleus accumbens (NAcc) DA overflow but do not produce drug conditioning. RESULTS: Both IP and VTA AMPH exposure sensitized locomotion and NAcc DA overflow, but only IP AMPH exposure produced conditioned locomotion. Importantly, whereas IP AMPH exposure increased spine density and dendritic length and branching in the NAcc, exposure to VTA AMPH produced the opposite effects. A similar differentiation of effects was observed in cortical areas. CONCLUSIONS: Together these findings suggest that the morphological changes seen following IP AMPH exposure reflect associative drug conditioning rather than nonassociative drug sensitization. The decreases observed in the NAcc of VTA AMPH exposed rats may reflect the inability of these infusions to support conditioning.
Artificial Brain 10 Years Away
It was declared at a TED talk, so it must be true!
Active Ingredient In Cannabis Eliminates Morphine Dependence In Rats
Injections of THC, the active principle of cannabis, eliminate dependence on opiates (morphine, heroin) in rats deprived of their mothers at birth. The findings could lead to therapeutic alternatives to existing substitution treatments…. (continues @ ScienceDaily)
Reading Pigeons’ Brains as They Fly
How homing pigeons find their way back to a starting point is not completely known. Studies have shown that the birds variously use the position of the Sun and the Earth’s magnetic field as a compass, and sense of smell and visual cues as navigation aids. But the use of visual cues has been difficult to study, because if a bird flies over a landmark and doesn’t change its course, it’s impossible to know whether the bird has not perceived the cue or is ignoring it.
The researchers developed tiny neurologgers, to record electrical activity in the pigeons’ brains as they flew. The birds also carried small global positioning system units to track position. By matching brain activity to location, the researchers could determine the effect of flying over a landmark.
The birds’ flights began over water, a relatively featureless environment, and then continued over land to a homing point. This enabled the researchers to determine brain activity as the birds reached the coastline and then flew over other landmarks.
They found that activity in both high- and mid-range frequencies occurred as the birds passed over a landmark. The researchers, who reported their findings in Current Biology, suggest that the mid-range frequencies are linked to the perception of visual information, while the high-frequency activity may be related to cognitive processing — perhaps the recognition of a landmark as something the bird has seen before…. (via NY Times)
Dolphins Maintain Round-The-Clock Visual Vigilance (via ScienceDaily)
Dolphins have a clever trick for overcoming sleep deprivation. Sam Ridgway from the US Navy Marine Mammal Program explains that they are able to send half of their brains to sleep while the other half remains conscious. What is more, the mammals seem to be able to remain continually vigilant for sounds for days on end.
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