Rats were given the commonly used chemotherapy drugs adriamycin and cyclophosphamide and while on the drugs, rats who were trained to prefer a light room to a dark room forgot their training.

"When animals are treated with chemotherapy drugs, they lose memory," Gregory Konat said in a statement. "When we add N-acetyl cysteine during treatment, they don't lose memory."

N-acetyl cystein is a modified form of the dietary amino acid cysteine.

Dr. Jame Abraham of West Virginia University's Mary Babb Randolph Cancer Center said as the term "chemobrain" entered the national lexicon, many patients expressed frustration about doctors not taking the complaints seriously.

"In the past, there was a lot of ignorance among doctors about chemo-induced cognitive problems," Abraham said in a statement. "In some patients, problems can persist for up to two years."

Some 40 percent of cancer patients undergoing chemotherapy complain of symptoms such as severe memory and attention deficits, but previously, scientists suspected the cancer, rather than chemo drugs, might be the cause, Abraham said.