Dendritic Spines (IMAGE) Howard Hughes Medical Institute Caption Nerve cells lacking fragile X mental retardation protein have too many dendritic spines, small signal-receiving spindles coming off the main tendril (top). But treatment with a drug called JQ1 reduces the number of spines (bottom). Scale bar is 10 micrometers. Credit Credit: Korb et al./ Cell 2017 Usage Restrictions Use with credit. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.