Erythrocyte nuclei resemble dying neurons in embryonic dorsal root ganglia

Cell death or apoptosis is regarded as an important feature of mammalian neural development, but the evidence for this generalization depends on the assumption that cell death can be clearly recognized. The usual profile of a dying neuron is a deeply stained pyknotic homogeneous sphere. In this paper we present evidence that such profiles in embryonic rat T₆ and L₄ dorsal root ganglia are not dying neurons but rather nuclei of immature red blood cells. This observation, combined with recent work showing that the methods previously used for counting normal or dying neurons are biased, indicates that the classic work establishing the importance of apoptosis needs to be repeated.