A new bulk-driven input stage design for sub 1-volt CMOS op-amps

This paper presents a new design approach for a rail-to-rail bulk-driven input stage using a standard single-well (n-well in this paper) CMOS technology. This input stage can provide nearly constant transconductance and constant slew rate over the entire input common-mode voltage, operating with a wide supply voltage ranging from sub 1-volt (V/sub T0/+ 3V/sub DSsat/) to the maximum allowed for the CMOS process, as well as preventing latch-up.

Developmental switch in the kinase dependency of long-term potentiation depends on expression of GluA4 subunit-containing AMPA receptors

The AMPA-receptor subunit GluA4 is expressed transiently in CA1 pyramidal neurons at the time synaptic connectivity is forming, but its physiological significance is unknown. Here we show that GluA4 expression is sufficient to alter the signaling requirements of long-term potentiation (LTP) and can fully explain the switch in the LTP kinase dependency from PKA to Ca2(+)/calmodulin-dependent protein kinase II during synapse maturation. At immature synapses, activation of PKA leads to a robust potentiation of AMPA-receptor function via the mobilization of GluA4. Analysis of GluA4-deficient mice indicates that this mechanism is critical for neonatal PKA-dependent LTP. Furthermore, lentiviral expression of GluA4 in CA1 neurons conferred a PKA-dependent synaptic potentiation and LTP regardless of the developmental stage. Thus, GluA4 defines the signaling requirements for LTP and silent synapse activation during a critical period of synapse development.