Figure 2.

LRP1 deletion leads to age-dependent dendritic spine degeneration and synaptic loss. A–D, Representative images of Golgi-impregnated pyramidal neurons in layers II/III the of cortex (A, B) and CA1 region of the hippocampus (C, D) from 18-month-old Cre⁺ and Cre⁻ mice. Spine density was quantified along dendrites from Cre⁺ and Cre⁻ mice (n = 5). Note that the spinal density was significantly decreased in Cre⁺ mice. E, Expression of synaptophysin and PSD-95 in the cortex was evaluated in 18-month-old Cre⁺ and Cre⁻ mice by Western blotting. Equal amounts of protein in this and subsequent figures were loaded to each lane. F, Densitometric quantification of synaptophysin and PSD-95 expression was performed as described in Experimental Procedures (n = 4). Note that the expression of synaptophysin and PSD-95 was significantly reduced in Cre⁺ mice. Scale bars, 1 μm. The data represent the means ± SD of at least four separate animals. *p < 0.05.