Integration of local inputs in visual cortex

In mammalian visual cortex, local connections are ubiquitous, extensively linking adjacent neurons of all types. In this study, optical maps of intrinsic signals and responses from single neurons were obtained from the same region of cat visual cortex while the effectiveness of the local cortical circuitry was altered by focally disinhibiting neurons within a column of known orientation preference. Maps of intrinsic signals indicated that local connections provide strong and functional subthreshold inputs to neighboring columns of other orientation preferences, altering the observed orientation preference to that of the disinhibited column. However, measuring the suprathreshold response using single-cell recordings revealed only mild changes of preferred orientation over the affected region. Because strongly tuned subthreshold inputs from cortex only marginally affect the tuning of a cortical cell's output, it is concluded that local cortical inputs are integrated weakly compared to geniculate inputs. Such circuitry potentially allows for the normalization of responses across a wide range of input activity through local averaging.      

Prenatal diagnosis and fetal outcome of cystic adenomatoid malformation of the lung: case report and historical survey.

Diagnostic ultrasound allows prenatal diagnosis of cystic adenomatoid malformation of the lung from the second trimester onwards throughout pregnancy. If the diagnosis is made before the 24th week of pregnancy, counselling often results in termination of pregnancy. Whether or not this attitude is in agreement with good medical practice is discussed on the basis of our own experience and a review of the literature.