Current in vivo methods for imaging the visual cortex lack the ability to map response properties at the level of single cells. A new technique using two-photon imaging of calcium signals has now overcome this limitation.

The concept of excitotoxicity, first established by the pioneering work of John Olney, traditionally has been applied to lesions of the CNS, focusing mostly on glutamate as a neurotoxic excitatory amino acid neurotransmitter. Indeed, glutamate excitotoxicity remains one of the best-supported theories for motor neuron death in amyotrophic lateral sclerosis (ALS), and was the pharmacologic inspir...

Previous work has suggested a role for retrograde synaptic signaling via endogenous cannabinoids in regulating the inhibitory control of neuronal activity. In this issue of Neuron, Chevaleyre and Castillo provide evidence for another form of endocannabinoid-mediated depression of hippocampal inhibition, which is activity dependent and long lasting.

Anecdotal and indirect empirical evidence suggest that excitement and market bubbles are intertwined, such that excitement not only arises during bubbles but may also help fuel them. We directly test the impact of excitement on bubbles in a bubbleprone experimental asset-pricing market (Capinalp, Porter, and Smith, 2001). Prior to trading, participants are assigned to emotion inductions through...